1) Move all the crypto classes from securesms.crypto.
2) Move all the crypto storage from securesms.database.keys
3) Replace the old imported BC code with spongycastle.
1) Change all instances which use concatenation to build strings
with variables in them to use string formatting instead.
2) Extract all string literals from layouts and menus into strings.xml
3) Extract all string literals from code into strings.xml
