L10n fr text compression

This was announced in #1280 

Also, I took the liberty in the EN text of fixing a number of incorrect/obsolete/suboptimal link targets, and add Stylus to the listed CSS preprocessors and nginx to the listed GZip-Static-style serer config references (as nginx is very much used for static assets and pretty much invented the gzip-static approach).

BTW, that EN markup is the most horrid sort of 1995-style code… lists in paragraphs, unclosed list items, format-only B's and I's, multiple line breaks instead of pars, bolds and breaks instead of headings… Upgraded it all in the FR text but didn't dare touch the EN text more than was necessary. Surprised at seeing that level of HTML "hillbilliness" on HTML5Rocks though :disappointed: