Merge pull request #1 from etoile/gh-pages-tweaks

Website tweaks
Deleted accidentally imported file
Cleaned CSS, index.html and reworked Frameworks section
Updated Download section
Small alignment and color fixes in Download section
Reorganized Download section to be more compact, fixed some container size issues and tweaked readability with CSS shadows
Improved element positioning at various sizes in Download section
More adjustments to get a good looking Download section independently of the device size
Finished footer section
Cleaned CSS
Converted font sizes to em
New optimized layout for small device sizes
Website text: revise, up to the end of the "User Experience" section. I left the old versions in comments for comparison