debug mode for wq/pages.js & wq/app.js (fixes #25)

 - multiple verbosity levels for wq/store.js debug
clean up api per docs

 - differentiate wq config from wq/app.js config
 - make hooks overrideable via config
 - don't export functions that aren't part of public API
 - see http://wq.io/docs/app-js and http://wq.io/docs/config
option to sync form submissions in background
allow same page transition in pages.register fn