Update modernizr.js to v2.7.1.
Update Respond.js to v1.4.1.
Losslessly compress images/xas.png.

Before: 162189 bytes
After:  134681 bytes
Merge pull request #222 from XhmikosR/xas.png

Losslessly compress images/xas.png.
Merge pull request #221 from XhmikosR/update-libs

Update libs