new(View.__): allow innerHTML to be rendered if need be...

for example:
  __ '.mydiv', innerHTML: 'a necessary evil...'
new(View): View.watch() convenience method for watching expressions that are cleaned up when the view is destroyed.
new(exts/x_model): For text input's, change model on keyup (instead of on change)
update todos
new(defineView-builder-plugin): outcss config can specify css filename or function to be called with css contents
updated todos
fix(cell/View): __ rendering of an undefined child
Updated todo: revisit Ext API!
Updated tood: revisit spy.watch and x_model APIs
revisit(cell/Ext): API changed, see https://github.com/peterwmwong/cell/blob/ab4186f802259c9462562b1b9fa6a6b53d70e47e/docs/TODO.md#revisit-ext-api

deps(coffee-script): 1.6.1