https://bugzilla.gnome.org/show_bug.cgi?id=687520

Add private replacements for deprecated functions such as
g_mutex_new(), g_mutex_free(), g_cond_new() etc., mostly
to avoid the deprecation warnings. We'll change these
over to the new API once we depend on glib >= 2.32.

fix warnings for all plugins that use: setlocale (LC_ALL...

Don't inlcude locale.h which we include in gettext.h if needed. Guard the
inlcude like we do in the simillar headers in core.

Original commit message from CVS:
add some i18n headers