*EXPERIMENTAL*
Implemented basic push notification stuff.
This is not useable at all for now and the code is a mess!
updated sender id
updated TODO
implemented authentication with google account
implemented push settings (mostly ui only)
minor fix
implemented (un-)registering process
added PushService
started working on the notifications
fix method call
implemented saving notifications to the db and reading them out
added pending intent to clear notifications data from  database
fixed tweet sorting
optimized notification layout
Implemented handling of notification types
handle error code 420 as specified by twitter
added missing dependency
Merge branch 'master' into push

Conflicts:
	res/values/strings.xml
	src/de/vanita5/twittnuker/activity/support/HomeActivity.java
resolved merging conflict
Merge pull request #13 from vanita5/master

option to refresh timeline before streaming starts