ticket:6 added login via Facebook
ticket:6 minor app logic changes
ticket:6 major work on network communication
Merge remote-tracking branch 'origin/master' into t6_sos_api_request

Conflicts:
	p2psafety-android/p2psafety/AndroidManifest.xml
	p2psafety-android/p2psafety/src/ua/p2psafety/SendMessageFragment.java
	p2psafety-android/p2psafety/src/ua/p2psafety/SosManager.java
	p2psafety-android/p2psafety/src/ua/p2psafety/util/Utils.java
ticket:6 added location sending and canceling sos on server
ticket:6 save current event in preferences; minor workflow and visual changes