* Pull out base class MimeEntryProcessor out of AppMetaMimeCreator.
* Pull class MimeInfoUpdater out of UpdateMimeInfoThread and derive it
from MimeEntryProcessor.
* MimeInfoUpdater: Instead of BMimeType::GuessMimeType(), use
Database::GuessMimeType() directly.
* This pulls in some more stuff, like libicon and agg which are also
included in libbe_build, now.
* Update a few libbe_build classes and headers needed to get things
building.
* This likely breaks the <build>mimeset build on Haiku.
