remove unused plugins from the tuts
add text tut
merge
merge, remove unused plugins from text tut
merge from master
expand markdown and html cells in text tut
add section on sharing to main tut
add section on the start page and generally working with the web browser to the main tut
expand and rewrite autotranslation tut
Merge pull request #595 from twosigma/spot/579

more tutorial work