basic beam code / untested
basic beam code / untested
use different filter for nfc intents
Merge branch 'nfc' of https://github.com/siacs/Conversations into nfc

Conflicts:
	src/main/AndroidManifest.xml
fixed merge error
unfinishd qr code implemenation. thanks to @emdete
fixed nfc. react to ?join uris. some refactoring. code cleanup. thanks to @emdete