Remove option to select (legacy) APG as crypto provider
Remove legacy APG interface
Remove APG permission
Remove unused strings
Use collections instead of arrays to enable stronger typing and reduce cruft
use isEmpty instead of size() == 0 for clarify
removed unneeded variables and clarified names
simplify following code review
EnumSet is more efficient than HashSet
Revert accidental change
Set interface makes more sense for flags
fix tests on JVM
add unit test
warn if not serializable, also add basic unit test
chain the exception
fix test that failed due to certificate expiry
Get more dependencies from jCenter
address review comments
remove controversial methods
further simplification