Added support for the WebRTC 1.0 certificate management API, as noted…

… in: Issue #195

Added certificate argument to the RTCDtlsTransport constructor, as noted in: Issue #218
Added the "failed" state to RTCDtlsTransportState, as noted in: Issue #219
Changed getNominatedCandidatePair to getSelectedCandidatePair, as noted in: Issue #220
Added support for WebRTC 1.0 RTCIceCredentialType, as noted in: Issue #222
Clarified behavior of createAssociatedGatherer(), as noted in: Issue #223
Changed spelling from "iceservers" to "iceServers" for consistency with WebRTC 1.0, as noted in: Issue #225
Added support for SCTP port numbers, as noted in: Issue #227
Changed "outbound-rtp" to "outboundrtp" within the Statistics API, as noted in: Issue #229
Changed maxPacketLifetime and maxRetransmits from unsigned short to unsigned long, as noted in: Issue #231
Clarified DataChannel negotiation, as noted in: Issue #233
Added getContributingSources() method, as noted in: Issue #236
Fixes to Examples 5 and 6, as noted in: Issue 237 and Issue #239
Fixed cut and paste errors in Example 11, as noted in: Issue #241