Fix typo in con-student that broke problem load.

Fix up some indenting.
Merge branch 'master' into jingxian2
Merge branch 'master' into jingxian2
The file dojo-install-version should *not* be in git.
Use "git commit -a" or "git add" to avoid this kind of
error.  Don't use "git commit ." and the like.
Rename Undo button to "Clear" in algebraic editor
Merge branch 'master' into jingxian2
Code review for renaming Undo button.
Bug Fix 2381
Simplify code for typechecker.  Moved dom.byId() into
checkInitialValue.
Bug Fix 2381
Code review for inputting units bug.
Added a comment with explanation.
Adding message from PM to fix bug number 2396.
Merge branch 'bvds'
Merge branch 'haoxuan2'
Merge branch 'master' into bstrong
Code review for fix targe node strategy bug #2396.
Removed redundant hint line (this is why there were two
copies of the hints).