[Bugfix beta] fix map: turns out 0 is also falsey
Make Ember.Namespace#toString ember-cli aware
Clarify {{action}}s use a quick way to add _one_ event to an element.

Direct readers to Component for more robust event handling.
[Bugfix Beta] avoid unneeded Function#apply
[Bugfix beta] stop using Binding#directionMap once binding per instance
use faster x[y] over y in x, as all hits will be explicitly truth
[DOC] Change 'the the' to 'the'