bugfix: scroll momentum increase over fixed elements

For more info see https://github.com/janpaepke/ScrollMagic/issues/164
enhancement: better way for clicks on mobile

As suggested by Kai: https://github.com/janpaepke/ScrollMagic/issues/169
added: new example

tinkapp.com
enhancement: updated parallax sections example

This solution works better for responsive environments, because the
tween doesn’t need to be updated, if the duration changes.
Also added note about ios8 in mobile examples.
change: ticker replaced with requestAnimationFrame

The tickers and setTimeouts were removed and replaced by
requestAnimationFrame.
This should solve the „juggy" behavior described here:
https://github.com/janpaepke/ScrollMagic/issues/167
added: favicon
changed: replaced requestAnimationFrame polyfill

Instead of changing the global variable ‚requestAnimationFrame‘ a
private function is now used to ensure functionality even if the user
decides to use different polyfills.
added: support for asynchronous loading

Defined both modules using UMD.
They are now defined as browser globals as well as using the AMD
pattern.
See here for more info:
https://github.com/janpaepke/ScrollMagic/issues/160
added: warning for tweens being overwritten

when scrolling fast scenes with conflicting tweens would cause problems.
With GSAP 1.14.0 this can be detected and a warning is displayed,
offering a solution.
See here for more info:
https://github.com/janpaepke/ScrollMagic/issues/145
updated: build file to show js errors for source

jshint is now also run for the source files to display errors with the
correct line numbers.
build v1.2.0