[Buildroot] libglib2 now requires gettext

[idunham at lavabit.com]

I've been trying to build a system with buildroot 2011.05rc2, complete
with GTK2, which requires libglib2; gettext is enabled for some other
library.
So far, buildroot has reached configuring libglib2 for the target system;
here, it ignores the --disable-nls flag, and goes on to:
...
checking for libintl.h... no
configure: error:
*** You must have either have gettext support in your C library, or use the
*** GNU gettext library. (http://www.gnu.org/software/gettext/gettext.html)

This with is libglib2-2.28.6

So I guess the makefiles need to be changed so as to set gettext as a
dependency for libglib2, if buildroot uses the latest version.