functions: allow using sub-dir of a module

Some projects' module (eg. newlib) are checked-out into a sudirectory
rather than into their own directory. Handle this case in the CT_GetCVS
function.

reporter_name="Matthias KAEHLCKE"

reporter_url="http://sourceware.org/ml/crossgcc/2008-08/msg00055.html"

reporter_comment=""