For those working on the Yii port, please don't work on the logic parts of the back-end yet.  I'm pretty much completely rewriting them in the limesurvey_dev_tms branch - removing all legacy Conditions, Mandatory, Array_Filter etc. code (e.g. removing about 50% of the logic, database calls, etc.).  I should be done in about a week, and then you can use the limesurvey_dev_tms branch as the "gold standard"  for porting the logic  (assuming that I might not have the time to do the EM port myself).