Fix issues with "Totals" section in QUnit Reporter

* Total # covered lines, and total # all lines were being incremented incorrectly, resulting in incorrect totals.  This was due to the `totals.totalSmts` and `totals.numberOfFilesCovered` variables being incremented *inside* the loop that was iterating through the statements per file.  Instead, this incrementing should happen after the loop is complete and the totals for that file have been calculated.  Then we add the totals for that file to the global totals.

* Branch totals were not being calculated when branch tracking enabled.  Added support for reporting global totals for covered branches and total branches.