Update README.md
Remove unused images.
Remove unused CSS.
Losslessly compress images.

Before: 22,3 KB (22.842 bytes)
After:  18,0 KB (18.453 bytes)
Switch to 4 spaces for indentation and trim trailing tabs.
Lots of css changes.

Add missing vendor prefixes, reformat everything.
Fix validation errors.
Update Bootstrap to v2.3.2.
Remove unneeded script type and merge two scripts in footer.
js: fix JS warnings and reindent.
Use html5shiv from jsdelivr.
about.php: reindent for better readability.
Update README.md.
Update hint.css to v1.3.0.
Be consistent with the fork me syntax.
Remove unused CSS.
cache.php: reformat.
Reformat and improve files.
sponsor.php: reformat and fix validation errors.
Use github-fork-ribbon instead of the image.