- compiler now returns a deferred for optional chaining and easier testing,
 * modified project tests accordingly, now all passing
 * cleanup in pre processor, project, and compiler

- modified bom generation (in compiler) so it generated end data based on the actual instances in the assembly, and not just counting instances
 * fixes #75
 * also fixed accidentally removed project:loaded event binding in coffeescad.app.coffee

-small fixes to deferreds in backbone.dropbox (now using deferred.reject() instead of fail() -> ouch, was completely wrong)
 * small amout of other related cleanups
- cleanup and fixes to the bom exporter:
 * now , it works again, yay !