get file extension associations working on more apps

Based on the comment in OpenPGP Keychain's AndroidManifest.xml:

  Do _not_ set mimeType for .gpg! Cyanogenmod's file manager will only show
  Keychain for .gpg files if no mimeType is set! For OI Filemanager it makes
  no difference, .gpg files can't be associated.

I ended up making entirely duplicate sections, one with a mimeType and the
other without.  This does seem to fix things on OI File Manager and ASTRO. I
wonder what it is going to break...

refs #1646, #1455
show Toast on failure to get the full GnuPGKey

A bad or corrupt key will cause GnuPG to barf, so catch it and warn the
user.  A partial download from a keyserver is one such example.

fixes #3052
handle importing large keys from the keyserver

Originally, it was just putting the whole text from the keyserver into the
Intent's EXTRA_TEXT.  This was rapidly running into size limits, and
throwing strange exceptions like:

"FAILED BINDER TRANSACTION!" android.os.TransactionTooLargeException

fixes #3046
enable GnuPG's built-in translations

libgpg-error and gnupg both include their own text strings as well as their
own translations of those text strings.

refs #1448
purge references to iconv, its not needed, Android is UTF-8

iconv is a library for converting between different formats.  Since Android
should be all UTF-8, there should be no need for iconv.  Its been working
so far without it, so I'm purging the iconv stuff.

Here's the thread:
http://lists.gnupg.org/pipermail/gnupg-devel/2012-January/026529.html
http://www.gossamer-threads.com/lists/gnupg/devel/56909
REMOVE ME/DO NOT MERGE debug flags for native builds

Do not ever include this commit in the official repo!  Its for debugging only!
REMOVE ME/DO NOT MERGE enable debug logs

Do not ever include this commit in the official repo!  Its for debugging only!