Plugin system

As well as providing dedicated stream creation functions, BASSWEBM supports the BASS plugin system, adding WebM and Matroska support to the standard BASS stream creation functions: BASS_StreamCreateFile, BASS_StreamCreateURL, BASS_StreamCreateFileUser. This is enabled using the BASS_PluginLoad function.

When the plugin system is used, the first playable track is played from the file, equivalent to using track=0 in a BASS_WEBM_StreamCreateFile call.