Fixed setting date in the past disabling the lock

Fixed iPad keyboard hiding

Previously there was no way to bring it back after dismissing it

Added check that new passcode is different

Changed viewLoaded to isViewLoaded

Fixed title for lockscreen with a navbar

Code cleanup, improved the custom number of digits

Callback for enabling passcode

Added `enablePasscodeWhenApplicationEntersBackground`. It does the opposite of `disablePasscodeWhenApplicationEntersBackground`.

Keychain entitlements added for the demo app

Changelog updated, comments added

Merge pull request rolandleth#150 from Sweeper777/master

Just fixed some localisation errors in Chinese