Use themed context when creating EmailAddressAdapter

Previously the activity theme was used to display the auto-complete
suggestions. This lead to unreadable text when the activity theme was
different from the "composer theme".
Fix condition on when to show "check mail" in POP3 accounts
Avoid NullPointerException in SubjectComparator
Don't create folder -NONE- when excluding special folders from a search
Get rid of accidentally created "-NONE-" folder
Don't crash when being started by an old unread widget intent
Fix NPE introduced in 340d6e0522b7cb03349e6f60ee169e8b7452fbcb
Merge remote-tracking branch 'upstream/master'