[ADDED] OS X: Master password input and changing.
[ADDED] OS X: Autocompletion by searching Core Data for previously
used sites.
[ADDED] OS X: Working password generation for sites.
[FIXED] Bad ciphering on little endian machines: Convert bytes to
network endian before using them as numbers.
[FIXED] Opening of Core Data store when iCloud is unavailable.
[MOVED] Key logic now in a common class extension on MPAppDelegate
so it can be shared between iOS and OS X apps.
[MOVED] MPConfig for sharing between iOS and OS X apps.
[CHANGED] keyphrase -> key.
