Dojo charting examples
Plot line chart
deleting node from dom
Merge branch 'master' into megha
deleting node from canvas and model
Merge branch 'master' into megha
updating model after deleting node
Code review for delete button.
Brought model update back into main.js.  Not tested yet.
Merge branch 'megha'
Add deleter
Didn't remove all references to session and model in draw-model.js
Fix bug where deleted model not sent to server.
Merge branch 'master' into sachin
Merge branch 'master' into sachin2
Merge branch 'sachin' into sachin2
Merge branch 'sachin' of github.com:bvds/LaitsV3 into sachin
Merge branch 'sachin' into sachin2
fix bug 2370
Fix to bug #2370
Cherry-picked from commit 82f8f3a546401ae33370655b3e832d3c055819ee
Also some minor cleaning up of other code.
Fixing time step in introductory problems, removing duplicate nodes in prob 108.
Merge branch 'master' of https://github.com/bvds/LaitsV3