$LANGUAGE should take precedence over $LANG

When activity bundles are loaded, the activity name and summary are pulled from an MO file that is associated with locale. However, sometimes locale, which uses $LANG has been superceded by $LANGUAGE as set in extensions/cpsection/languages/model.py. This patch looks for MO files associated with $LANGUAGE before $LANG so that the proper MO file is used.

This problem is seen on the .AU systems which use en_AU for locale and en_GB for LANGUAGE.