include scrypt library in source tree (temporarily)

will figure out a proper distribution method later
patch scrypt helper functions to accept char[]s instead of Strings
edit TODOs to be grep friendly
basic symmetric key derivation and persistence based on password
initialization is handled by the ICachedSecrets impl
port sample to PBE secrets
use 96-bit nonce value for GCM
order stubs in order of the state changes
make usage of PassphraseSecrets easier as the default impl in the handler
generate a 256 bit AES key

with upcoming sqlcipher+iocipher support, they'll want a 256 bit key
so we might as well make this the default for now.
Merge branch 'crypto'

Conflicts:
	cachewordlib/src/info/guardianproject/cacheword/CacheWordService.java