Build a tree structure for better path generation.
Needed a toString() method for State to get the alreadyVisited hash table working correctly.
Minor HTML changes
variable rename
Reamde changes
Fixed bug on failure to find button entry

"next" corrected to "continue" (keyword).
Also, terminated several statements with semicolons.
Added Wheatstone layout

Create Wheatstone and Jeffries layouts from a common base. Add a
selector to control layout choice.
Merge branch 'master' of https://github.com/Foehg/fingering into Foehg-master

Conflicts:
	fingering.js