Merge pull request #443 from uberspot/master

CertifyKeyActivity sets error if no key is selected
Cleanup SelectSecretKeyActivity and also return Uri
Blocked ok button for generating weak (<1024) RSA key.
Note about blocked possibility to generate weak (<1024) RSA key.
Merge pull request #445 from gogowitczak/rwrsa-branch

Disabled possibility to generate weak RSA keys (512 and 1024 bit)
use correct LongSparseArray for minimum api level
Merge pull request #448 from AlexanderS/lint-fixes

use correct LongSparseArray for minimum api level
Cleanup
Remove oxygen text from icon
Merge branch 'master' of github.com:openpgp-keychain/openpgp-keychain
add apg's fix for Key id display