Loading catalog add-ons needs to be hybrid build aware

[bonefish]

When starting a gcc4 application on a gcc2 hybrid Haiku, liblocale needs to load gcc4 versions of the catalog add-ons, hence:

• HaikuImage must be adjusted to add the add-ons for the alternative gcc.
• RosterData::InitializeCatalogAddOns() must check for the ABI and load the respective add-ons. (e.g. cf. BTranslatorRoster::Private::Private()).

[pulkomandy]

done in hrev37490