Expand the message bundle system to be able to locate the bundle for a requested language

The current system requires a user to pass in the location of the specific message bundles that are to be used by the prefsEditor, panels, and etc. However to support a language adjuster for the First Discovery Tool http://issues.fluidproject.org/browse/FLOE-281 we'll need a system that is more robust.

Instead a user should pass in a reference to the base name of message bundle, from there the system will go through an algorithm trying to locate the correct bundle and falling back to a default one if the desired langauge is not located.

e.g.

fr-ca is requested.

will look in this order for the message bundle fr-ca -> fr -> en (default)

Additionally the prefsEditor will need to take in a default language as an option, so that we'll know what to fall back to. However, the current language setting will first look into a model value (so that this can be part of a store preference) to set the components language.