Workaround: item clicking didn't work in spark-menu

onClick and onMouseUp have inexplicably stopped firing in <spark-selector>, but onMouseDown is fine, so use that for now.
Merge pull request #1992 from ussuri/fix-clicking-not-working-in-menu

Workaround: item clicking didn't work in spark-menu
Implemented projects separators (fixed #1555)
Resolve most of the nagging dart2js warnings during `grind deploy`
Merge pull request #1996 from ussuri/warnings-in-dart2js-run

Resolve most of the nagging dart2js warnings during `grind deploy`
review comments
Merged
Merge pull request #1993 from dinhviethoa/1555-files-view-separator

Implemented projects separators in files view
Update files_controller.dart
Renamed cannot_launch.html -> *.htm to prevent pub processing
Merge pull request #1999 from ussuri/warnings-in-dart2js-run

Renamed cannot_launch.html -> *.htm to prevent pub processing
Fix broken push.
move the send feedback action
Merge pull request #2001 from devoncarew/devoncarew_move_feedback

move the send feedback action
Throw exception in git clone for submodules.
Show error on clone if repo contains submodules.
Merge pull request #2000 from dart-lang/git_push

Fix broken push.
adding main entry library for docs and fixed library name for menu separator
Merge pull request #2004 from financeCoding/spark_widgets_lib

adding main entry library for docs and fixed library name for menu separ...
reorder import/export