Add mention logos at the bottom of the landing page.
Fixed the title of the landing page.
Merge branch 'develop' of https://github.com/thegooddata/webapp into develop

Conflicts:
	TGD/themes/tgd/css/main.css
main.css corrections
Added a bit of space between mentions
Edited the gigaom logo.
Removed Chango and Zidisha logos.