add more official Guardian Project keys to the included public key ring

This gives people a trusted way to import our public keys, since they'll
be embedded in the app.
make DebugLogActivity's import key default to the included public keyring
ImportFileActivity: use MIME type if file extension is not recognized

If the data coming in has a MIME type that is supported, then it should be
imported regardless of the file extension.

refs #1455
add strings for the PGP MIME types, file extensions are not so simple...

for .sig, .skr, and .pkr, there is a direct mapping for file extension to
MIME type.  For .pgp, .gpg, and .asc, each file extension can map to
multiple file extensions... sigh... yes its true...

refs #1455 refs #1456
don't add the setup and install Activities to the history

once the user has gone thru them, they should forget they ever existed...

Perhaps we should also remove them from Recents, I'm not sure there.
route known key files to ImportFileActivity, all else goes to FileHandlerActivity

Unfortunately, this can't all be nice and neat since .asc, .gpg, and .pgp
files can all have multiple contents (keys, sigs, or encrypted data). Also,
since these Activities just serve as data routers, keep them from being
added to the history and recents.

refs #1455 refs #1456
add two example files for detached signatures: .sig for binary, .asc for ASCII
make GnuPG.gpg2() return the POSIX exit value for testing success/failure

This lets us do quick and dirty things like "gpg2 --verify"
add basic VerifyActivity to check .sig files

This currently just works with file:// Uris, and probably only files that
come in via the .sig file association in AndroidManifest.xml.  This is just
a rough version to get the ball rolling. Once GnuPGData can handle files
and streams directly (#1581) then this should be converted to always use
Streams, e.g. by using getContentResolver().openInputStream(uri)

refs #1569
verify .sig and .asc detached signatures, and prompt to view file if good

This verifies the .sig and .asc "--detach-sign" format of files, provided
the signed file is present as well.  If that's successful, then it'll
prompt the user to view the file or not.

refs #1569
add Transifex config file for the 'tx pull' tool
escape " quotes in strings.xml so that they show up in the interface

Otherwise, they get stripped out by something.
remove \n from strings.xml, they usually break in translations

The only formatting character that should be included in a strings.xml
string is \" for adding quotes and printf-style format strings.  Newlines,
\n, tabs, etc. should not be included since they are usually messed up in
the process of translating.
fix warnings in first_run_welcome_activity.xml, including unneeded TableLayout
standardize on "Gnu Privacy Guard" as the name of the app
gnupg-for-java: use POSIX FILE streams when creating GnuPGData for files

Previously, GnuPGData(File f) would load the entire contents of the file
into memory, then pass a memory gpgme_data_t to gpgme.  This is horrible when
working with large files or machines with limited memory.  This patch uses
the gpgme function for creating a gpgme_data_t from a POSIX FILE stream.
add the gpg2 exit value to Gpg2TaskFragment results
gnupg-for-java: expose gpgmeOpDecryptVerify as a proper Java method

Currently this will throw an Exception if the verify fails. We need to
implement gpgme_verify_result_t in Java, like GnuPGGenKeyResult.java in
order to get useful information about the verification process.

refs #1567
add methods to create PGP ASCII pattern matchers to detect ASCII contents

A .asc file can be a lot of things, so we need to look at the embedded
headers in order to see what the contents is. This will be very heavy on
large files, but since we're aiming for ease of use, I think its
worthwhile to include.  Plus, large files should be binary, not ASCII.

refs #1569 refs #1455 refs #1456
make EncryptFileActivity receive files via an Intent

This allows other internal Activities to call it to handle encrypting
files.

refs #1454