configure doesn't correctly determine mingw64

changes the search pattern for host_os from *mingw32* to *mingw* so that mingw64 can be used, and any mingw32 variable name change to mingw.

conformity update for mingw32 variables to mingw

changes the search pattern for host_os from *mingw32* to *mingw* so that mingw64 can be used

Fixed VS2015 build

Leading to extra work when copying between versions of VS.

Solution: remove second unnecessary definition.

Solution: add missing project files

(Also, updated FD_SETSIZE to 16K as a bonus.)

Problem: not building on VS2015

Solution: fixed project files, and warning in timers.cpp

Revert "Revert "Problem: deprecated use and reference of `zmq_term`""

Revert "Problem: deprecated use and reference of `zmq_term`"

Problem: deprecated use and reference of `zmq_term`

Solution: Replace with `zmq_ctx_term`

Solution: replace with `zmq_ctx_term`

Also fix whitespace (tabs instead of spaces)

Solution: replace all occurrences with `zmq_ctx_term`

Solution: replace all occurrences with `zmq_ctx_term`

fixed issue #1754

Problem: deprecated `zmq_utils.h` is still included

Solution: remove all remaining references to `zmq_utils.h`

Problem: various errors in build scripts

- zmq_utils.h was removed
- udp_address.cpp and udp_engine.cpp were added

Solution: patch all affected build scripts

Added "udp_address" and "udp_engine" to VS2015 project

I hope restoring this from a previous version doesn't do any damage, it
is missing in the current version of this repository and is vital for
the lib to compile anywhere.

Altered VS2015 files to enable building of the library.

Problem: `zmq_utils.h` is deprecated since 2014-07-09

Solution: remove this file

Since they are allowed

(They are not, however, allowed in hostnames)

Fix unused-parameter/unused-but-set-variable/missing-field-initializers warnings

ctest: Add missing test_udp and test_large_msg

Problem: `udp_address::interface` conflicts with VS2015 build.

This commit addresses the following warnings reported on gcc 5.2.1. In
the future, this will help reduce the "noise" and help catch warnings
revealing a serious problem.

It was originally introduce in the refactoring associated with
zeromq/libzmq@da2bc60 (Removing zmq_pollfd as it is replaced by zmq_poller).

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/path/to/libzmq/src/socket_poller.cpp: In member function ‘int zmq::socket_poller_t::add(zmq::socket_base_t*, void*, short int)’:
/path/to/libzmq/src/socket_poller.cpp:92:51: warning: missing initializer for member ‘zmq::socket_poller_t::item_t::pollfd_index’ [-Wmissing-field-initializers]
     item_t item = {socket_, 0, user_data_, events_};
                                                   ^
/path/to/libzmq/src/socket_poller.cpp: In member function ‘int zmq::socket_poller_t::add_fd(zmq::fd_t, void*, short int)’:
/path/to/libzmq/src/socket_poller.cpp:108:50: warning: missing initializer for member ‘zmq::socket_poller_t::item_t::pollfd_index’ [-Wmissing-field-initializers]
     item_t item = {NULL, fd_, user_data_, events_};
                                                  ^
8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---

This commit addresses the following warnings reported on gcc 5.2.1. In
the future, this will help reduce the "noise" and help catch warnings
revealing a serious problem.

8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---
/path/to/libzmq/tests/test_stream_exceeds_buffer.cpp: In function ‘int main()’:
/path/to/libzmq/tests/test_stream_exceeds_buffer.cpp:19:9: warning: variable ‘rc’ set but not used [-Wunused-but-set-variable]
     int rc = setsockopt(server_sock, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(enable));
         ^
8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---

This commit addresses the following warnings reported on gcc 5.2.1. In
the future, this will help reduce the "noise" and help catch warnings
revealing a serious problem.

8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---
/path/to/libzmq/src/options.cpp:1048:36: warning: unused parameter ‘option_’ [-Wunused-parameter]
 bool zmq::options_t::is_valid (int option_) const
                                    ^

/path/to/libzmq/src/plain_client.cpp:146:30: warning: unused parameter ‘cmd_data’ [-Wunused-parameter]
         const unsigned char *cmd_data, size_t data_size)
                              ^

/path/to/libzmq/src/plain_client.cpp:146:30: warning: unused parameter ‘cmd_data’ [-Wunused-parameter]
         const unsigned char *cmd_data, size_t data_size)
                              ^

/path/to/libzmq/src/socket_base.cpp:1445:44: warning: unused parameter ‘group_’ [-Wunused-parameter]
 int zmq::socket_base_t::xjoin (const char *group_)
                                            ^
/path/to/libzmq/src/socket_base.cpp:1451:45: warning: unused parameter ‘group_’ [-Wunused-parameter]
 int zmq::socket_base_t::xleave (const char *group_)
                                             ^

/path/to/libzmq/src/radio.cpp:145:33: warning: unused parameter ‘msg_’ [-Wunused-parameter]
 int zmq::radio_t::xrecv (msg_t *msg_)
                                 ^
/path/to/libzmq/src/dish.cpp:164:32: warning: unused parameter ‘msg_’ [-Wunused-parameter]
 int zmq::dish_t::xsend (msg_t *msg_)
                                ^

/path/to/libzmq/tests/test_msg_ffn.cpp:32:16: warning: unused parameter ‘data’ [-Wunused-parameter]
 void ffn(void *data, void *hint) {
                ^

/path/to/libzmq/tests/test_timers.cpp:50:19: warning: unused parameter ‘timer_id’ [-Wunused-parameter]
 void handler (int timer_id, void* arg)
                   ^
8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---

This commit fixes the author warnings reported below. These tests
have originally been introduced in zeromq/libzmq@5ebfd17 and
zeromq/libzmq@5fe75f0.

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CMake Warning (dev) at tests/CMakeLists.txt:133 (message):
  Test 'test_udp' is not known to CTest.
This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Warning (dev) at tests/CMakeLists.txt:133 (message):
  Test 'test_large_msg' is not known to CTest.
This warning is for project developers.  Use -Wno-dev to suppress it.
8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---