Unsupported compiler as a warning

Rather than throwing out an error, it would be nicer to just warn the
user about that unsupported compiler, in this fashion htq2 will be open
to compile with any C/C++ compiler.
Unsupported compiler as a warning

Rather than throwing out an error, it would be nicer to just warn the
user about that unsupported compiler, in this fashion htq2 will be open
to compile with any C/C++ compiler.
Compiler test added

After setting up the compiler (whatever it is), its name will be put to
to the test.
Header probe

Standard C headers on target platform will be probed to see their
existence, and therefore, their inclusion on prereqs.h. Their symbols
are prefixed with HT_ to avoid name collision.
New version schema

Versions will be in x.y.z-a1 format. "0.1.0" will be the first milestone
instead of the former 1.00.
Merge branch 'cc_unk' of github.com:alericoveri/hecatomb into cc_unk

Conflicts:
	cmake/Config.cmake
	src/include/config.h.in
Update HT_HAVE_EXECINFO
i386 was still present
Correct use of 'defined' preproc operator

I was getting to used to C89, I didn't know this could be so delicate.
Merge branch 'cc_unk'