Solution: run Valgrind only on the default Linux build to avoid
increasing the runtime.

Solution: import ax_valgrind_check.m4 macro file to provide a
conveniente automake hook to run Valgrind on all tests.
Add --enable-valgrind to ./configure call and then run make
check-valgrind to run memcheck, helgrind, drd and sgcheck on all
tests. Run check-valgrind-memcheck to run only memcheck.

Fix usage of IPv6 addresses

Problem: test_large_msg requires 2GB of free RAM

Use FILENAME_MAX to determine BUFSIZE when getting socket path.

Solution: remove temporarily until proper message limits have been
implemented, then a more granular test case can be added without
such high requirements which are problematic in embedded environment,
build systems, VMs and CI systems

Problem: IPC wildcard test broken on OSX

Solution: increase path buffer length to 73

Update Unix Domain Socket creation/handling

Updated handling of Unix Domain Sockets, make use of temporary directories, and cleanup afterward.  Fix test_term_endpoint handling of optvallen

Add code coverage to build system and CI

Solution: add it

Solution: add new coverage build, and upload results to coveralls.io

Solution: import ax_code_coverage.m4 from autoconf-archive and use it
in configure.ac and Makefile.am in order to provide a make
check-code-coverage target behind a --enable-code-coverage configure
flag, that can be used to generate a gcov/lcov code coverage report.
Depends on having gcov and lcov installed.

Problem: Windows PDB not created for RELEASE targets

Solution: Modified projects to create PDB file for RELEASE targets
	- also spread precompiled settings to all DevStudio solution versions

This change affects Windows builds only

parameter naming consistency [aesthetic]

Problem: make dist does not tar up macros.hpp

Better comments for understanding the classes array_t<> and array_ite…

Solution: run make dist-check, which will run additional tests,
including making sure that the library is installable and the
distributable tarball is buildable, along with the usual make and
make check.

Solution: simply run make VERBOSE=1 check instead of manually
checking for return value and cat'ing the log file. With VERBOSE, on
error the log file will be automatically printed.

Solution: add the document files to the MAN_DOC and MAN_HTML targets
in doc/Makefile.am only if BUILD_DOC and INSTALL_MAN are set,
otherwise leave the targets empty to avoid errors in make distcheck.

Solution: add it to Makefile.am file list

Problem: CMakelist missing support for Windows Precompiled headers

Solution: Add precompiled flags to CMakeList.txt for faster compiles
+ bonus - removed compilation warning on Windows by adding
	 add_definitions (-D_WINSOCK_DEPRECATED_NO_WARNINGS)

Problem: Tests do no build in Windows environment

Solution: Modified CMakelist.txt to build correctly for Windows
- corrected CMake required version to make sure it builds in
  Ubuntu 14.04 LTS with no warnings.

Solution: Modified CMakelist.txt to build correctly for Windows

Problem: Windows Build not using precompiled headers for all targets

Problem: Added "make clean" to Windows build scripts

Solution: Enabled precompiled header settings in all targets
Before build time: ~6min 49 secs
Stop  Time: Fri 03/04/2016  8:29:50.13
Start Time: Fri 03/04/2016  8:23:00.28

After build time: ~4min 19 secs
Stop  Time: Fri 03/04/2016 12:12:10.24
Start Time: Fri 03/04/2016 12:07:51.78

Solution: Added ability to do equivalent of a "make clean" by executing:

O:\git\libzmq\builds\msvc\build>buildall.bat clean
Start Time: Fri 03/04/2016 14:33:56.50
Cleaning without libsodium
Cleaning ..\vs2013\libzmq.sln... ()
Platform=x86
Configuration=DynDebug
Configuration=DynRelease
Configuration=LtcgDebug
Configuration=LtcgRelease
Configuration=StaticDebug
Configuration=StaticRelease
Platform=x64
Configuration=DynDebug
Configuration=DynRelease
Configuration=LtcgDebug
Configuration=LtcgRelease
Configuration=StaticDebug
Configuration=StaticRelease
Cleaning complete: ..\vs2013\libzmq.sln

Stop  Time: Fri 03/04/2016 14:34:01.84
Start Time: Fri 03/04/2016 14:33:56.50

A clean takes ~5 secs to complete.

Problem: Visual Studio Toolset was incorrectly set in VCXPROJ files