Cleanup and fixes of optimizations

* remove comments/console.debug
* only remove `null` when it's an unseen instance -- if it's a refresh,
  then explicitly use `removeAttr` on the instance
* use `using` helper in */info.mustache -- unsure why, but it works
  with live-binding of `null` values where other methods don't
  (probably because the parameter becomes a can.compute -- e.g. other
  helpers would likely work here also)
Merge remote-tracking branch 'origin/develop' into feature/maybe-performance
Cleanup checking of null/undefined
Merge pull request #294 from reciprocity/feature/maybe-performance

A few fixes for the optimizations -- Brad, you're too fast!