Code cleanup

Add const qualifier to source parameters for z85 encode/decode

Reset metadata for outbound messages

Bugfix wrong CMakeLists.txt after rename of file

Documentation patches

Renamed test case to actually explain what it's testing, and cleaned up
the code a little.

Solution: change setsockopts on printable keys to expect 41, nor 40
bytes. Code still accepts 40 bytes for compatibility, and copies the
key to a well-terminated string before using it.

Fixes #1148

Code cleanup

Provide socket option for pub sockets to not silently drop message

Document altered HWM behaviour when ZMQ_ROUTER_MANDATORY is set.

Add test for HWM behaviour for mandatory ROUTER sockets over tcp

moved root CMakeLists.txt tests config to tests/CMakeLists.txt

Update zmq_msg_get(ZMQ_SHARED) to return true for type_cmsg messages

define encoding for message metadata to be UTF8

use enum retired_fd instead of -1

clarifies that these are text fields,
and removes ambiguity about how to create proper
text object from stored bytes.

Problem: does not install man pages correctly when out of tree

Solution: fix Makefile.am

As per Richard Sharpe on zeromq-dev.

z/OS: Updated to build libzmq git master

Updated:
    builds/zos/README.md: Updated with portability notes resulting
       from building zeromq/libzmq/master as of 2014-07-23 on z/OS
       UNIX System Services.

       Current z/OS UNIX status: all expected tests pass, except
       "test_proxy", which hangs and times out.

Updated:
    src/thread.cpp: On older z/OS UNIX System Services,
        pthread_{get,set}schedparam is not present (searching the
        Internet suggests it may be present in later version than
        the one being used for z/OS UNIX System Services porting).

        Make zmq::thread_t::setSchedulingParameters() a no-op on
        z/OS UNIX System Services.

    NOTE: pthread_{get,set}schedparam appear to have been introduced
    by POSIX.1-2001 or IEEE 1003.1-2004 so may not be universally
    available, and thus more platforms may need this "no-op" treatment.