Fix compilation error with "void setnetgrent" / "void endnetgrent"

Code assume that the functions "setnetgrent" and "endnetgrent" return
int. On some platform (some bsd, android, ...) the return type is void.
This patch fix the compilation issue by testing return type with autoconf
add a test for bionic before including netinet/ip.h
Redmine#1884: Add ^context=xyz specifier to module protocol, with acceptance test
Remove test for Enterprise.

There is no compile test anymore, and I can't see a reason why this
code should not be in both versions.
Cpu, load and process gathering monitoring unit tests
Avoid appending empty include dir to CPPFLAGS

Previously, this resulted in invalid compile options such as the following tokyocabinet test:
gcc -o conftest -pthread -g -O2 -O2 -DNDEBUG   -I/usr/local/include -I    conftest.c -ltokyocabinet
Fix file descriptors leaks
Redmine#3273: acceptance test for lsdir()
Code to parse CSV-formatted strings (redmine feature #3272)
Fixing a problem with dlclose and avahi

In situations where dlopen does not fail but does not load the library,
the handle will be NULL (see issue 3337 in Redmine).

This fix checks if avahi_handle is not NULL before calling dlclose in order
to avoid the agent from crashing unnecessarily.

Once this is integrated into master this needs to be cherry-picked into 3.5.x.
Merge pull request #900 from cduclos/avahi-crash-on-dlclose

Fixing a problem with dlclose and avahi
Adding 32 bits path to avahi paths

Currently we were looking only into 64 bits path for finding the avahi library.
This fix adds at least the 32 bits path from ubuntu to the resolution.
Merge pull request #901 from cduclos/avahi-dlopen-does-not-fail

Adding 32 bits path to avahi paths
Merge pull request #897 from jeffali/csv_parser_seq

Code to parse CSV-formatted strings (redmine feature #3272)
Prevent container variables from being assigned to indexed l-values
Prevent non-container variables from being assigned to an index of an existing container variable name
Cleanups in EvalContextVariableGet/Put
Cleanups in iteration land
Add JsonSelect, unit test

Javascript style indexing
Add container subindexing in iteration, acceptance tests