getHtmlFromRange should use CodeMirror's version of truth

resolves https://github.com/firebase/firepad/issues/117
resolves https://github.com/firebase/firepad/issues/85

also add a spec for this
Start work on headless module
Simple delete/insert setText in headless mode
trying to setup get/set html
More work on headless setHtml
Don't tread on global.document
SetHtml in headless crudely works
factor out some common text marshaling code
Bug in requiring npm Firebase
break out html serialization into its own module
Fixes for entities and text piece parsing
make sendOperation take a callback
Add integration specs for headless mode
Make grunt auto-update examples dir too