Some fixes and improvements

• Removed classList dependency
• Removed (Collapse, Modal) or minimized (Affix, ScrollSpy) the effect of resize handlers on IE8, so that it should really be usable
• Replaced the synthax highlighter for the demo with PRISM
• Included a CSS "polyfill" for Bootstrap 3 to render normal layout on IE8 without respond.js
• Fixed the Collapse resize handlers for both click and resize
• Added some addClass / removeClass utility functions for the Button, ScrollSpy and Tab, modern browsers really need & work with classList
• fixed Collapse overflow and other code improvements
• changed Button's change event to bs.button.change, it works better than the native change
• minor Carousel improvements, if no CustomEvent found, script should still work without element does not support that property error
• minor change to Scrollspy
• Demo features minifill, a 5k polyfill for IE9-
• Improved/updated demo
• Documentation updates