Merge pull request #51 from ashh87/master

Updates spongycastle to the fork:
https://github.com/ashh87/spongycastle

This allows us to import secret keys much more quickly and to enable passphrase changing for subkey only secret keys.
move ActionBarSherlock lib, add gradle build files
Update README for gradle
Check gradle version before building
Better than version check: gradle wrapper
gradle wrapper
gradle wrapper
Crypto Provider implementation start
Process safe implementation of PassphraseCacheService, First test for crypto provider
debug infos
update API
Check if passphrase is needed in PassphraseCacheService, extend documentation
rename to openintents namespace
Better API demo, open activity from service, discover crypto provider with packagemanager instead of register intent
Rename foir clarification
Fix activity manifest entry
Possible to add allowed packages
some fixes all over
Add database columns for crypto consumer preferences
More work on crypto consumers