0.5.13 * adds Ogg Opus

Set up a logging abstraction, OGVLogger Accessible from OGVKit.singleton.logger; override the default logging level by eg: OGVKit.singleton.logger.level = OGVLogLevelDebug; This is done in the example application. By default, only errors and fatals will be logged to console. You can subclass OGVLogger and substitute an alternate place to put the logs if you like. Log messages are now distributed among debug, warning, error, and fatal levels. May adjust details later. Fixes #116

0.5.11 tag - enable libvpx threading 

clarify that opus is in webm only so far, need to add to ogg 

Tag 0.5.9 Fix regressions in audio, threading, high frame rate files.

Tag 0.5.8: audio fixes 

fix & tag 0.5.7 - seek at end fixes Fixes an edge case in seek to end where no returned packets would cause an attempt to start playback data at -1 instead of the target time, which threw an assertion fail.

fix & tag 0.5.6 - end of file kitty demo * v0.5.6 end-of-file fixes with some edge cases fixes #158

Tag 0.5.5 - MP4 & audio fixes * v0.5.5 initial MP4 support, various seek & audio fixes

bump 0.5.4 includes webm brute force seek