User: Clean up coding style and documentation

* Parameter type hint should be a variable type or a class
  name. Types Null, Bool, Boolean, Int, Integer, String do
  not exist and are invalid values. Changed to their PHP
  type names (basically just lowercase).
* Made inline comments consistently use "//" instead of "#".
* Removed various odd spurious spaces sequences in @param
  lines. They are sometimes used to pretty-align multi-line
  descriptions. Though I think that is silly, I've left those
  alone. I've only removed the spaces where it seems arbitrary
  and not aligning with anything. Last I checked the common
  convention for multi-line descriptions is to simply continue
  on the next line with one extra space as indention.
* Swapped "$var Type" in cases where the surrounding @param's
  already use "Type $var".

Change-Id: I6b315e308271194815879c509d3ac6aeb409851b
Merge "User: Clean up coding style and documentation"