Fix for StrictMode error.

When the device lost connectivity, a StrictMode error could be thrown since
the stream was never closed.
Update Korean translations
Update Ko translations (complete list)
Modify Korean translations on Classes
Modify Korean translations
Fix Korean translations
Center folders without status (e.g. outbox) in folder list again.
Fix message list item background color
Fix and vastly simplify the query for the threaded message list

This requires another database schema change. With this change messages
at the root of a thread reference themselves in the 'threads' table,
i.e. 'root' contains the value of 'id' for these messages. It makes
selecting all messages in a thread much simpler.
Change style for button bar in setup (Android 3+)

Use the button bar layout from Roman Nurik's WizardPager example:
https://code.google.com/p/romannurik-code/source/browse/misc/wizardpager
Use theme-specific image for 'add contact' button
Disable server side full text search for the moment

The server search itself does work. But the results are not displayed
to the user because only the message headers of found messages are
downloaded and the subsequent search in the local database won't return
those messages.
Merge pull request #276 from Uni-/master

Update Korean translation
Merge pull request #211 from colund/master

Close stream in case of an exception
Enhancement for charset fallback.
Fallback rule is defined in CHARSET_FALLBACK_MAP.
Multi-level fallback is supported.
Java5 style 'for'
Code cleanup
Move KOI8-U -> KOI8-R fixup to charset fall-back table
Fix "Empty trash" functionality for POP3 accounts

Previously messages in the local Trash folder were marked as deleted,
then deleted from the server. During the next sync the placeholders for
deleted messages are removed from the database.
Obviously this doesn't work for POP3 accounts because the Trash folder
can't be synchronized with the server. So, for POP3, we now immediately
clear out all messages in that folder.
Hide delete policy "Mark as read on server" for POP3 accounts