support for mathjax
updated MathJax to 2.3, slim copy feat. MathML input, SVG output, STIX fonts
Merge pull request #34 from pkra/feature/mathjax

updated MathJax to v2.3
Merge branch 'develop' into feature/mathjax

Conflicts:
	lib/Readium.js
	readium-js
Merge branch 'develop' into feature/mathjax

Conflicts:
	lib/Readium.js
	readium-js
split two mathjax options: multiple files, single file.
set single file option as a current one
loading mathjax on demand
fixed left/right reflowable page spread margins

fixed left/right reflowable page spread margins, by using transparent borders instead of percentage width based on some arbitrary (and somewhat incorrect) ratio.
submodule
removed wrapping buttons on links
replaced SVG buttons with glyphicon font, now colorized appropriately in night mode (theme), also fixed title bar dark colours.
"real" default theme (authored styles, no Reading System override)
submodule
RTL TOC items
ah, removed "focus" indicator on page buttons, because Chrome shifts the keyboard focus even during mouse interaction
Implement iframe content, script, and reading system object injection.
submodule
updated keymaster lib
Merge branch 'feature/iframe_injection' into feature/mathjax

Conflicts:
	lib/EpubReader.js
	lib/Readium.js
	readium-js
Update Readium.