Added coming soon to worksheets column; changed footer logos.

deleted old msr logo; added about link to base.html.

updated graphic to .png to get transparent bg.

changed coming soon logo to blue.

shuffling logos around

removed stanford and chalearn from footer:
:

Deleted un-used docs images folder.

removed unused logo image

deleted unused graphics
Merge pull request #492 from willum070/comingsoon

Added coming soon to worksheets column; changed footer logos.