Reorganized sections; styled footer
Fixed missing CSS class for footer menus
Add correct links to repositories
Updated footer disclaimer
Content for community page with all links
Added content to resources/tutorials page
Restyled headers and lists in pages: languages, community, tutorials
Removed obsolete and empty pages
Hid all dead/temporary links
Changed index content: very minimal presentation of ReactiveX
Fixed Rakefile condition
Drafted frontpage parts, and make first section header
Minor improvements to the Observable section on the frontpage
Drafted the list of famous Rx users
Icons wand, join, ear, for headers CREATE, COMBINE, LISTEN
New background image for jumbotron on frontpage
Refactor styles from frontpage to frontpage-diagram.less
Drafted the Ubiquitous section
Drafted the remaining sections on the frontpage
Wrote content for Ubiquitous frontpage section