remove duplicate ipbasic entry
[mms] Moved MIME ID manipulation/query methods out of Horde_Mime and into Horde_Mime_Id.

Horde_Mime is now solely meant for base (RFC 2045-2049) MIME encoding methods.
Remove preg matching in MIME decode method.
Improved unit test for MIME encoding/decoding
Don't unattach onload event

I can't personally reproduce, but these DOM image elements are temporary
(they are destroyed when the message is removed from the cache) so no
need to cleanup this minimal amount of memory