Merge pull request #57 from derrh/master

Adds masquerading support in the client.
Added ics calendar link to CKIUser

refs #MBL-1677
Merge pull request #58 from mileswright/master

Added ics calendar link to CKIUser
support locked_for_user in CKIAssignment model
Merge pull request #59 from nlambson/master

support locked_for_user in CKIAssignment model
Add path for quizzes