video.js 5.12.0 on Node.js NPM

@misteroneill, @brandonocasey, and @pagarwal123 updates all the code to pass the linter (view)
@misteroneill added ghooks to run linter on git push (view)
@brandonocasey removed unused base-styles.js file (view)
@erikyuzwa, @gkatsev updated CSS build to inlcude the IE8-specific CSS from a separate file instead of it being inside of sass (view) (view2)
@gkatsev added null checks around navigator.userAgent (view)
greenkeeper updated karma dependencies (view)
@brandonocasey updated language docs to link to IANA language registry (view)
@gkatsev removed unused dependencies (view)
@misteroneill enabled and updated videojs-standard and fixed an issue with linting (view)
@misteroneill updated tests to qunit 2.0 (view)
@gkatsev added slack badge to README (view)
@gkatsev reverted back to qunitjs 1.x to unbreak IE8. Added es5-shim to tests (view)
@gkatsev updated build system to open es5 folder for bundles and dist folder other users (view)
greenkeeper updated uglify (view)
greenkeeper updated grunt-concurrent (view)
greenkeeper updated karma-chrome-launcher (view)
@gkatsev added tests for webpack and browserify bundling and node.js requiring (view)
@rlchung fixed tests that weren't disposing players when they finished (view)