Auto-select first auto-added required param and fix param order

Symptoms:
* When adding a template with required parameters, the last parameter
  is initially focused
* Parameters and parts appear out of order, and adding/remove/moving
  them shows them in almost random placement

Diagnoses:
* Parameters are auto-focused when added, and parameters are auto-added
  in forward order
* TransclusionModel's process method had a bug in which the code to
  derive an offset from the item being removed would not be reachable
  due to an inverted logic statement

Prognosis:
* Fatal, with a 10% chance of survival

Treatment:
* Set focus on the first parameter after auto-adding required
  parameters to a template
* Invert the logic in TransclusionModel's process method, so that if
  the index IS undefined we will proceed to define it

Change-Id: I299053b63045ec933747831f1b4aa63493760f8b
Merge "Auto-select first auto-added required param and fix param order"