add support for context enabled actions
doc and style cleanups
Merge branch 'master' into context-menu
add context menu ux; merge to master
nits
Build version 0.0.12
css hover changes
Merge pull request #261 from dart-lang/css-selections

css hover changes
Merge branch 'master' into context-menu
review comments
reviews comments
Merge pull request #249 from dart-lang/context-menu

Context menu
implement close
merge master
Implemented drag&drop inside the treeview
Added TODO and comment
fixed close to show only for top level items
Merge pull request #262 from dart-lang/closeFile

Implement Close file
Temporarily switch to importing polymer_elements from GitHub rather than Pub

Pub's version fell behind the current SDK. Should revert once it catches up.
Merge pull request #265 from ussuri/fix-polymer_elements

Temporarily switch to importing polymer_elements from GitHub rather than Pub