libc: create an infrastructure to build and install the libc locales

This patch adds a common glibc/eglibc infrastructure to build and install the
libc locales.

Signed-off-by: "Benoît THÉBAUDEAU" <benoit.thebaudeau@advansee.com>

reporter_name="Ioannis E. VENETIS"

reporter_url="http://sourceware.org/ml/crossgcc/2009-11/msg00109.html"

reporter_comment=""