load global native libraries as soon as possible

Now that the libraries are included via ndk-build in the libs/ folder, and
unpacked from the APK by Android, that means the libs are guaranteed to be
in place before this app ever runs. So the libs can now be loaded as early
as possible by sticking them in a static{} block in GpgApplication.

refs #1548
comment on confusing part of partially implemented sync code

closes #2753
REMOVE ME enable debug logs
recruit unused KeyListActivity become SelectKeysActivity

It turns out that the built-in Contacts picker cannot handling selecting
more than one contact at a time.  This suck for choosing who to encrypt to,
since you can encrypt a file to multiple people.  Therefore, we have to
implement our own Activity for choosing keys.

closes #1491 refs #1633
use an @string for the SyncService MIME types in XML files

Use a string resource for the MIME types so they they can be easily traced
through the program, and there are fewer definitions of the same string.
This leaves us two: one in Java space and one in XML space

This also purges the res/xml-v14/contacts.xml because it was a duplicate of
res/xml-v11/contacts.xml.  If android-14 features are needed, that file can
easily be re-added.
reorg "Encrypt File To" constants and strings for readability

SyncAdapterColumns doesn't say what the content is, and it'll only get more
confusing as we add more items to the Contacts.
kludge to prevent crash #1660 but instead give extra details to logcat

I have not been able to reproduce this, and this whole function should be
rewritten, so for now, just make sure there is no attempt to write beyond
the end of the array, and write errors to logcat when it happens.

refs #1660
replace crazy double loop with linked list when building keylists

The old code was buggy and difficult to read. This commit replaces it with
one pass of reading keys from gpgme and writing to a linked list. Then a
second pass that creates a fixed java Array and fills it from the linked
list.

closes #1660, closes #1621