- added calculation and display of available/used storage space to browserStore /fs
 * "hackish" way of calculating total available space in localStorage
 * display as a "progress bar"
 * modified projectBrowser to mach, updtated less/css styles
 * also various cleanups and improvement to the browserStore/base store, fs etc

- added "dependency injection" (a bloody parameter) to specify the appVent/pubsub systems, so stores do not need to explictely know about
the backbone marionette appVent (see previous commit messages about the decoupling of stores from the current app implementation)

- removed reference to remote (online) fonts in LESS/css (app needs to work offline too)
- browserStore save and load via UI is mostly functionnal (but potentially buggy)
 * added _dispatchEvent wrapper around backbone.marionette's vent system, so any pubsub system can be used
 * now correctly passing the main appvent instance to browserStore at creation time in coffeescad.app
 * pubsub events are now dispatched correctly from browserStore via the _dispatchEvent method (with gracefull failure in case no pubsub system was specified)
 * save and load thus seem to work correctly, but as the browserView is very messy right now , will need some checks
- some work done on refactoring the dropboxStore/fs:
 * almost there : listing projects and project files works, saving as well, plus some other helper methods
 * loging in /out works
 * loading needs some work
 * needs more overall cleanup/polish

- refactored some code from browser and dropbox fs into fsBase
- cleanup and fixes for the various base class calls and attributes (store name, type etc in particular)
- some minor css adjustements