Makefile: don't error when mkdir args are already on disk
Use SIP.js to make a video call
update phonertc submodule to joseph-onsip fork
Makefile: don't always run "init"

It must be now be done manually post-clone.
Update SDP assembling to split up video and audio candidates

See https://github.com/egreenmachine/sipjs-cordova/commit/7ba1e1343aab160a59a11502398ab423f285d39d
update phonertc submodule with NPE fix

See https://github.com/alongubkin/phonertc/commit/77f3e327921b243ce6ec99e17351a09e71bfd0e7#commitcomment-6829113