* Initial lms changes for Sailthru

* Fix identified code quality issues

* Fix migration failure

* Fix code quality identified issue

* Initial commit of Sailthru lms changes

* Field mapping changes for Sailthru integration

* Merge fix

* Add users to Sailthru list on registration

* FIx minor code format issues

* Several updates based on code review feedback

* Updates based on recomendations from Sailthru

* Clean up unit tests

* Fix last login

* Updates based on code review feedback

* Updates based on code review feedback

* Fix comment

* Cleanup

Please note that this is a squshed commit and the work of:
Symbolist, macdiesel, nedbat, doctoryes, muzaffaryousaf and muhammad-ammar

TNL-3190

TNL-3107

TNL-1988

TNL-1851