Highlight thumb during drag
Highlight thumb during drag

https://github.com/brion/ogv.js/issues/259

chrislearn/ogv.js,xzf158/ogv.js,paladox/ogv.js,paladox/ogv.js,chrislearn/ogv.js,chrislearn/ogv.js,paladox/ogv.js,paladox/ogv.js,xzf158/ogv.js,chrislearn/ogv.js,xzf158/ogv.js,xzf158/ogv.js,chrislearn/ogv.js,paladox/ogv.js,xzf158/ogv.js