changed dependency from ChangeSummary -> ObserveJS
Make the binding map be an object and not an array

This is a work around for a JSC bug when using arrays with hole in them
it sometimes "removes" the hole, changing [/* hole */, value] to
[value]. Thisonly happens in optimized mode. If the web inspector is
open we do not hit this bug.

BUG=https://github.com/Polymer/ShadowDOM/issues/203
TBR=rafaelw

Review URL: https://codereview.appspot.com/12580046
factored out Node-bind and PolymerExpressions
factored out Node-bind and PolymerExpressions, part 2
Reduce JSC workaround

Only `children` needed to change to an object.

BUG=https://github.com/Polymer/ShadowDOM/issues/203
TBR=rafaelw

Review URL: https://codereview.appspot.com/12762043
Template instances with undefined model value produce instances with zero nodes

Note: this removes template.clear() as it is no longer needed (t.model = undefined serves that purpose now).

R=arv
BUG=

Review URL: https://codereview.appspot.com/12797044
make naming consistent
fix benchmark js reference
Add test for binding to select.value

R=arv
BUG=

Review URL: https://codereview.appspot.com/12904043
fix DefaultStyle test on non-template browsers
name changes
Merge pull request #137 from Polymer/master

8/15 master -> stable