[+] Added support for Android 4.4
[+] Added a WebSMSBroadcastReceiver to get informed about the successfully send command, The Receiver will save the SMS as delivered
bump build tools, fix preferences on API19+
Merge remote-tracking branch 'mkl87/master'

multiple changes to merged code:

* add sms app chooser
* change some code to run only on API 19+
* sanitize code
* add siginature level permission to websms's broadcast
* add ads
* clean up

Conflicts:
	SMSdroid/src/main/AndroidManifest.xml
	SMSdroid/src/main/java/de/ub0r/android/smsdroid/Preferences11Activity.java