Swap GCC 4.2 backend for GCC 4.7.2 release (20-Sep-2012). No changes
were made to either GCC 4.7.2 code (yet), or GCCXML's, but a lot of
GCC's subpackages were removed, as per the previous GCCXML commit.
So no testsuite directories, and support for all languages, except
for C and C++, has been removed.

Lots of other GCC4.7.2 subpackages were also removed, to keep as much
as possible in-line with the previous GCCXML commit. GCC's intl/
subpackage was kept though, as I had linking issues without it.
This also provides internationalization support potentially useful to
GCCXML users.

N.B A lot of C language files (gcc/c-*.c) were moved to the
GCC/gcc/c-family/ directory.

Original CMakeLists.txt files were left in place.