Merge gccruntime patchset to 2012Q4.

Add USE_GCC_RUNTIME to print/ghostscript.

Add USE_GCC_RUNTIME to graphics/netpbm.

Add USE_GCC_RUNTIME to lang/perl5 with a caveat.

When using USE_PKGSRC_GCC_RUNTIME, you must also use an external
perl when building gcc, else perl-depends-on-gcc-depends-on-perl.

Add USE_GCC_RUNTIME to sysutils/coreutils.

Add USE_GCC_RUNTIME to databases/postgresql91.

Add USE_GCC_RUNTIME to lang/ruby18-base

Add USE_GCC_RUNTIME to lang/ruby193-base

Add USE_GCC_RUNTIME to devel/nspr.

Add USE_GCC_RUNTIME to multimedia/ffmpeg

Add USE_GCC_RUNTIME to devel/libuuid

Add USE_GCC_RUNTIME to textproc/py-cElementTree.

Add USE_GCC_RUNTIME to textproc/py-expat.

Add USE_GCC_RUNTIME to devel/py-readline.

Add USE_GCC_RUNTIME to databases/py-sqlite3.

Add USE_GCC_RUNTIME to databases/ruby-sqlite3.

Add USE_GCC_RUNTIME to lang/tcl.

Add USE_GCC_RUNTIME to databases/tokyocabinet.

Add USE_GCC_RUNTIME to databases/tokyotyrant.

Add USE_GCC_RUNTIME to multimedia/xvidcore.
Add USE_GCC_RUNTIME to x11/tk
Add USE_GCC_RUNTIME to chat/ejabberd
Add USE_GCC_RUNTIME to multimedia/ffmpeg010

This should not be necessary, but due to the way this package is
laid out, compiler.mk is read before USE_LIBTOOL is set, so we need
to add USE_GCC_RUNTIME early.  It should be possible to re-organise
the Makefile to avoid this completely.
Add USE_GCC_RUNTIME to databases/postgresql92
Add USE_GCC_RUNTIME to security/openssh
Add USE_GCC_RUNTIME to x11/py-Tk
Add needed USE_GCC_RUNTIME