On Firefox, fire onnegotiationneeded after the first data channel is created.
Bump version to 0.0.5.
Don't insert an additional onnegotiationneeded if the session already has a data m-line.
Avoid unnecessarily re-parsing SDP on every new data channel.
Merge pull request #2 from bemasc/bemasc-negotiation-needed

On Firefox, fire onnegotiationneeded after the first data channel is created