User Highlights and Log last page visited

New database tables, ajax controllers and javascript handlers to enable
user highlights and store user's last location in the book
Merge pull request #91 from ivipul/master

User Highlights and log last page visited.
Incorporate fix to color regression in turtle
ignore source/index.rst
Bug fix:  missing correct answer
Merge branch 'master' of github.com:bnmnetp/runestone

oday

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tree diagrams for self check question
Add instructions to create a new user account before it can be added to the instructor group
fixes bnmnetp/runestone#79
Revert accidental commit "fixes bnmnetp/runestone#79"

This reverts commit 2841e362287ea32bfd248e6e154d684f0b0dea1f.
fixes bnmnetp/runestone#79
Merge branch 'master' of https://github.com/isaacdontjelindell/runestone
Merge pull request #92 from isaacdontjelindell/master

Add some steps to README; fix issue #79
add a disqus comment box directive. Has only been registered in conf.py for the devcourse
disqus directive takes the 'shortname' parameter; add section about disqus box to overview.rst
merge
Merge branch 'master' of github.com:bnmnetp/runestone

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add disqus identifier to disqus Sphinx directive
typo
Merge pull request #94 from isaacdontjelindell/master

Add Disqus comment box directive