More precise complex :host selectors

Old selectors whould match even if some parents of the host had the attribute/class used.
Merge pull request #1368 from ussuri/more-precise-host-selectors

More precise complex :host selectors in widgets
Fix exception in spark-selector when firing an 'activate' event

Polymer couldn't serialize the entire activated item in all cases, in particular when the item was a Polymer element itself (e.g. spark-menu-item).
Merge pull request #1369 from ussuri/fix-exception-in-spark-selector

Fix exception in spark-selector when firing an 'activate' event
Revert "Merge pull request #1247 from devoncarew/devoncarew_git_archive_inflate"

This reverts commit bbb2866634376c0f3b0c46618a5cdc62e4f3d0b1, reversing
changes made to 71f3f868f0efb6e8ffaaf18396303064d0e5589e.

Conflicts:
	ide/app/test/benchmarks.dart
	ide/pubspec.yaml
Disabled benchmark tests