owr: Constify some static arrays
transport: Use the highest ranked, working decoder/encoder for VP8/H264 from the registry

This allows us to use existing codecs on the user's system, especially it
allows to use hardware codecs and removes a dependency on openh264.
configure: Properly align --enable-debug help string
owr: Conditionally build a static binary or not

Make the default no, so that a normal configure will work as expected
and builds a version that works out of the box with the system dependencies.

https://github.com/EricssonResearch/openwebrtc/issues/6
webrtc.js: handle invalid ICE candidates gracefully

On invalid ICE candidates invoke the failureCallback passed to addIceCandidate.
Also call completeQueuedOperation() so that the internal operation queue can
proceed and doesn't get stuck.
webrtc.js: Work around Chrome WebRTC bug #1142

https://code.google.com/p/webrtc/issues/detail?id=1142

Fixes interop with Chrome Android v37.0.2062.117, for example.

The RTCIceCandidate.candidate attribute as passed by Chrome for Android is of
the format `a=candidate-attribute', meaning that the actual candidate is
prefixed by a=.