more graceful initialization of modals
Prevent test/demo app config from leaking into consuming app.

As of Ember CLI 0.0.45 and up, the file located at
`config/environment.js` will be used to return the addon's own
configuration.  That conflicts with the way this library is using
`config/environment.js` (for the testing/demo app).

This simply overrides the default config hook to return nothing.
Merge pull request #75 from rwjblue/do-not-leak-config

Prevent test/demo app config from leaking into consuming app.
closes #77
releasing
adding nested outlet scenarios
speed up acceptance test animation
nested outlet support

Closes #41.
Closes #83
make modals opt-in

Related to #79. Related to #84.
documenting change
control class & id on containerless helpers
releasing
can't propagate id to children

because both will be in the dom together. duh. :-p
bugfix
add clarification to documentation about modals

Make it obvious in the example what you have to do with query params to get basic example to work.
cleanup previous documentation edit
closes #97
don't match initial render unless explicitly asked to
build against ember release channel by default