Minor wording changes to English translation of preferences strings

ChatViewer: Chat fragments updated only if they need to be updated (onChatChanged, onContactsChanged)

OTRManager: sessions are created again after "plaint_text" of "finished" status. Debug logging added.

Contact list navigation drawer "XMPP accounts" made clickable and lead to "XMPP accounts" preferences screen.

1.0.12

#456 Fix: hardware button menu fix: ContactList and ContactEditor  uses toolbar menu (setSupportActionBar removed).

 If contact is null no options menu created.

1.0.11

http://developer.android.com/design/patterns/navigation.html#into-your-app

Revert "Correctly use SRV specified hostname for cert validation (#204)"

Current chat notifications fixed (sound and vibration effect for new message in  current chat if the option is turned on). #446

1.0.10

1.0.9

Correctly use SRV specified hostname for cert validation (#204)