Enhancements to MultiLanguageSupport header/source code

* MultiLanguageSupport.h contain way to many unnecessary includes
* g_hLibIntl shouldn't be exposed. So added load/unload functions.
* All g_pf* pointers shouldn't be exposed. They are now internal.
* Some fixes for unused parameters.
* One fix for duplicate macro.

Signed-off-by: Tobias Lorenz <tobias.lorenz@etas.com>
Merge branch 'master' of https://github.com/rbei-etas/busmaster