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
Implement iframe content, script, and reading system object injection.
Merge branch 'feature/iframe_injection' into feature/mathjax

Conflicts:
	lib/EpubReader.js
	lib/Readium.js
	readium-js
Update Readium.
Update sub-module.
Update sub module.
Update Readium.
IMPORTANT: Allowing unsafe eval in chrome extension's CSP (this might be dangerous)
Update sub module.
Update Readium.
Revert "IMPORTANT: Allowing unsafe eval in chrome extension's CSP (this might be dangerous)"

This reverts commit b1598357f1eb42a1109e9a1920804596f7f269a2.
Update single-file MathJax to v2.4
fixes #90 (stacked details buttons)
addresses #91 (CSS cleanup)