Attach event listeners to <juicy-tile-list>s instead of window
Hover - highlight support for virtual containers #30
improve performance of click-blocking a little bit.
click -> select support for virtual containers #30
Chrome stable fix for weird Polymer flow:

attributeChanged callback was called before attached
Cleaner, faster blocking clickis over overlay - no longer blocks debugging;

unused getSortableElement removed
Fix nested selections
Change the way tree is build
Bind to juicy-tile-grid as well.
Fix juicy-tiles selection in shadowDOM and with templates
Remove unused attribute