The new options allows querying the maximum allowed number of sockets.
This is system dependent and cannot be encoded in the include file as a
preprocessor macro: for ZMQ_USE_SELECT, this depends on the FD_SETSIZE
macro at time of library compilation, not at time of include file use.

fix libzmq.pc generation under cmake

fix autotools out of tree build link issue on linux

Fix hang on terminate when inproc is connected but never bound.

added srcdir to --version-script=$(srcdir)/libzmq.vers

The ${libdir} was getting replaced/removed by configure_file() making pkg-config give bad flags: -L -lzmq
My fix was to add @ONLY to configure_file() so ${} style pkg-config substitutions are left alone.
In addition, I put the other typical ${} substitutions back into the libzmq.pc, since its now safe.

Revert "Fix potential memory leak"

This reverts commit 50d34e56.

Fix identity handling for inproc transport

Fixes #872

Added ZMQ_BUILD_TESTS to CMakeLists.txt to allow turning off tests. 

Added ZMQ_BUILD_TESTS to CMakeLists.txt to allow turning off tests. Useful when building ZMQ as a git submodule.

Fix potential segfault/memleak

Delete the socket if the initialization part of the socket creation
fails.

Call the allocation assertion macro before dereferencing the socket
pointer.

Fixed issue #868

Fixed issue #865 - validation on ZMQ_TCP_KEEPALIVE

Fix cmake build

Test for 127.0.0.1 at tests startup

Fixed man page for zmq_proxy_hook

- spaces instead of tabs for indentation
- fixed levels under EXAMPLE USAGE
- added to Makefile.am

[libzmq] const string p -> const string& p (#860)

add proxy_chain, a multi proxies chaining in the same thread feature

Man page fixes

add a proxy hook

Fixes to test cases

- renamed test_stream_disconnect_notifications (too long!)
- removed print statements in that test case
- fixed Makefile.am for test_zap_ipc_creds (was not building)