We now support extra-info documents and pluggable transports
We now support extra-info documents and pluggable transports

BridgeDB supports parsing extra-info documents which allows it to
retrieve information regarding the pluggable transports a bridge
accepts.

pagea/bridgedb,mmaker/bridgedb,wfn/bridgedb,pagea/bridgedb,wfn/bridgedb,mmaker/bridgedb