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) Broke out the UI elements of the major Activites into stylable
attributes.
2) Created a 'light' and 'dark' theme for the newly stylable attrs.
3) Touched up some of the UI spacing.
4) Implemented dynamic theme switching support.
1) Consolidate all of the KeyCachingService interaction into a single
mixin. Activities extend delegates which call through to the mixin.
2) Switch Activity increment/decrement triggers from onStop to onPause
in order to account for some screen locks that don't stop activities.
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
