convert KeyListFragment to plain ListFragment style

The ListFragment has lots of sensible defaults that we want to use, and
they making adding things like live search filters much easier.  In this
case, its actually using SherlockListFragment since Sherlock is used
elsewhere.  If we rip out ActionBarSherlock, then this should work fine
just switching everything to the Android Support versions.

refs #1633, #2681, #1467
alpha sort lists of keys based on Contacts.DISPLAY_NAME

before, it was stored in the order that things were added, I think.
include skeleton keyserver Fragment with new Java keyserver support

This includes the KeyServer and HkpKeyServer classes from originally from
APG, but taken from OpenPGP Keychain.

closes #2756  refs #2808