TikaConfig should notify users if it cannot initialize some parser

It would be nice if TikaConfig would somehow signal that it cannot load parser classes. Currently it just silently ignores all throwables.

I would be ok with about any kind of signaling (even just wrapping and rethrowing the exception). If we wan't to maintain back compat in functionality we could indroduce a new config option into the configuration file or a method in TikaConfig class that would enable rethrowing exceptions on parser initializations.

What do others think?