Problem: getting a serialized integer from a zmsg is painful

Solution: add a simple decoder (zmsg_popint).
Problem: main README is badly formatted

There are numerous small issues in the source code (like blank line
at start of source) and the mkman script that cause the README.md
to be badly formatted.

Solution: fix these.
Problem: README TOC is mostly empty

Due to gitdown design the class sections don't appear in the TOC.

Solution: fix gitdown parsing.
Problem: TOC is hard to read

Solution: collapse only level 4 items
Fix ZSYS_SIGHANDLER env check
Merge pull request #734 from Vodalys/zsys_sighandler

Fix ZSYS_SIGHANDLER env check
Merge pull request #733 from hintjens/master

Documentation fixes
Fix typo error
Merge pull request #735 from aquette/master

Fix typo error
Automatically generate ChangeLog from git logs

The ChangeLog file is now automatically generated from git commit logs.
The target range of commit logs is specified using GIT_START_POINT in
Makefile.am, as the older boundary, up to HEAD. GIT_START_POINT can be
a date, a git tag, a git hash, ... See gitrevisions for more information
on specifying ranges

This work is inherited from the one of Charles Lepple, on the project
NUT - Network UPS Tools <http://networkupstools.org>
Add ChangeLog to the git ignored files
Disable distcleancheck due to the dist generated files

The automated generation of the ChangeLog file introduced an issue in
the distribution chain, leading to ChangeLog being left at distclean
time, while it should have been removed. The distcleancheck_listfiles
workaround (commented) works fine on modern systems, but may cause
issues on older unix systems. This commit disables distcleancheck, and
leaves to CZMQ maintainers the choice to enable distcleancheck_listfiles
or not
Merge pull request #736 from aquette/autogen-ChangeLog

Automatically generate ChangeLog from git logs
Fail if /dev/urandom could not be read

Make sure we do not succeed if /dev/urandom could not be read. Otherwise
we generate a uuid based on uninitialized data, which is not really
random.
Merge pull request #738 from numerodix/master

Fail if /dev/urandom could not be read
Only do a custom typedef of bool for MSVC

I changed the check for defining a non standard bool type to only be used with MSVC.
Doing so with mingw causes issues for the Go binding, as Go expects std bools to be used under mingw (As they are available)
Merge pull request #740 from PSG-Luna/patch-1

Only do a custom typedef of bool for MSVC
Replace spaces with tabs to ensure make doesn't refuse our file, add -lrpcrt4 flag to expose the CreateUuid funtion to the linker, use $(CC) instead of hardcoded gcc command
Merge pull request #741 from PSG-Luna/patch-2

Fix mingw makefile