Fix nfc, make edit activity like a modal dialog, move all menu actions into view activity
Rework menu items
Use PgpKeyHelper.splitUserId in EncryptAsymmetricFragment
Remove import activity from drawer, make it reachable from key list only
Use AppMsg in edit key
certs: ditch expiry, re-add data blob, improve ViewCertActivity

GnuPG doesn't support expiry of user id certifications. The number
of rings with an expiration subpacket in a cert out there is likely
negligible.

ViewCertActivity now verifies the key and displays a status. For
revocation certs, the revocation reason is also shown.
Merge remote-tracking branch 'origin/master' into certs

Conflicts:
	OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/provider/ProviderHelper.java