Switch to Polymer 0.10.0-pre.9
Remove the deprecated and unnecessary 'lightdom'
main(): remove initPolymer() and add @initMethod
Merge
Merge remote-tracking branch 'upstream/master' into update-to-polymer-0.10.0-pre.9

Conflicts:
	ide/app/spark_polymer.dart
Merge remote-tracking branch 'upstream/master' into update-to-polymer-0.10.0-pre.9
Switch from `import 'packages/'` to `import 'package:' for widgets

See related issue #500, which now seems to be fixed/required.
Remove bindKeybindingDesc(): caused NPE with Dartium + new Polymer; non-Polymery anyway

This will be redone in a Polymery way in the upcoming Polymer/non-Polymer code merge.
Undo an unintended change
Merge pull request #1657 from ussuri/update-to-polymer-0.10.0-pre.9

Some fixes prompted by update to polymer 0.10.0-pre.9