Fix the build by adding back a comma...
ASTUnit::getMainBufferWithPrecompiledPreamble: use MD5 hash of the remapped
files to tell if they were changed since the last time we have computed the
preamble

We used to check only the buffer size, so if the new remapped buffer has the
same size as the previous one, we would think that the buffer did not change,
and we did not rebuild the preambule, which sometimes caused us to crash.
Add a test I forgot to svn add in r197755
Fix documentation typos
Makefile.ocaml: Tweak to use --system-libs.
move test back into the parent directory and add a REQUIRES: obj emission.