Remove lang/gcc45 in favor of lang/gcc46 and later. Nothing in the
tree uses this version of GCC (GCC 4.5.x) any longer and GCC 4.6 has
been the default for USE_FORTRAN=yes and USE_GCC=4.X+ for a while
and has proven itself. Plus, only GCC 4.6 and GCC 4.7 have been
patched to work with FreeBSD 10.x and later.
Feature safe: yes