Added stopwatch, cleaned up edit delegation

- Added param to ->testPuzzle so as to pick from list of premade puzzles
- Reduced # of decimal point for stopwatch value.
- Improved comments in ->getHTMLSkelaton
- Removed ->getHTML
- Removed ->togglePossibles
- Removed appending classes in ->refreshDisplay to applying classnames
- Added cell param to ->calcPossibles so as to only calculate possibles
for cells affected by the current cell.
- Renamed ->solve to ->dumbBruteRecurse
- Added ->getBoxCells() method
- Added ->startStopWatch method
- Added ->stopStopwatch method