Updated about page text (Git #366).
Update: change 'experiment' to 'worksheet' globally in all visible .htm files.
Merge pull request #373 from willum070/docs

Updated about page text (Git #366).
Merge pull request #374 from willum070/globaltext

Update: change 'experiment' to 'worksheet' globally in all visible .htm ...
Merge branch 'master' of https://github.com/codalab/codalab into dev