optimization, only declare background creation method once
start work on video backgrounds #751
updated submodule link
add LocalConnection library: prepwork for a 100% client-side only off-screen notes viewer and presentation commander (using a second browser window, e.g. on a split screen)
add getTotalSlides #858
test for #858
Merge branch 'dev' of github.com:ht push origin akimel/reveal.js into dev
Merge remote-tracking branch 'remotes/SinnerSchraderMobileMirrors/original_dev' into hakim-dev

Conflicts:
	css/reveal.min.css
	js/reveal.js
	test/test.js
fix latest merge manually
whitespace police raid
manual tweak of fix grabbed from mainline for IE11/IE10
fix themes list: all themes should be separated by a '-' dash
the parallax image configured in the JS config object in the index (demo) page overrides any CSS-defined parallax image, if one is available: by removing the JS-config-specified one, the parallax demo theme finally works again.
- extend the fragments unit tests

- fix bugs regarding fragments: getIndices() and availableFragments() were not properly aware of *grouped* fragments: the unit tests have been extended to check these fixes

- boolean config param config.loop should just be checked for truthy/falsey value everywhere (some checks were overly specific)

- added assert() for debugging/testing assistance of the code

- config.touch fix: when this option is DISabled ALL related handlers should never be installed!
- added the classic Reveal.config JS-based parallax image demo as an extra example now that the main index has been fixed (and thus lost its parallax config element as it is meant to showcase various themes, at least one of which has a custom CSS-defined parallax background which was overridden by the Reveal.config JS setting in there.

- bit of RequireJS work, still not complete! (Turns out named define() calls don't work; the quickest way to resolve this is by using anonymous define()s only and then providing a 'map' to requireJS which tells it which required module is what/where. This first edit/fix fixed the zoom plugin and restored its functionality in the demo.