ignore cache files
fix #294 and a related issue
Merge pull request #295 from isaacdontjelindell/loginreq-issue-294

Fix #294.
Update preface text so it doesn't talk about app engine anymore.  Also give bare minimum instructor instructions for making their own course.
Merge branch 'master' of github.com:bnmnetp/runestone
Add javascript validation to test for spaces in Project Name field

fixes #296
Add instructors help page in FAQ form and add links to it from the help menu.
crap!  I checked the wrong file.  I didn't mean to commit databases.tbz!
remove databases.tbz
skulpt bug fix for using length as method in a user defined class
typos and instructor.html will always be in overview not in static/{{coursename}}
Add clarity to locations of book after initial build.
If the database is empty, add courses for thinkcspy, pythonds, and overview

fixes #298
Add version information to the instructor page.  This will help instructors know when to rebuild their course to keep up to date with the latest bug fixes.
change divid for stack active code so it does not conflict with mChoice
Ignore bad data in getaggregate

This may be due to duplicate div_ids or simply old data that does not conform to the standard for the act column.
A big more contact info.
Bug fixes for __iter__