- more work on fs/store refac:
 * attempting to find a better way to store file/folder hierarchies in local storage
 * started refactoring browserStore
 * progressively getting rid of all backbone/marionette elements in stores, to keep them
as independant from app structure as possible
 * added convenience method getFiles to the Project class (to avoid having stores and others
know about the internal "rootFolder", as that is bound to go away at some point)
 * various minor cleanups and refinements to storeBase and fsBase