Increase size of scrollbars on touch devices.

git-svn-id: http://blockly.googlecode.com/svn/trunk@1745 c400ca83-b69d-9dd7-9705-49c6b8615e23
Enable mouse wheel on flyouts with scrollbars.

git-svn-id: http://blockly.googlecode.com/svn/trunk@1746 c400ca83-b69d-9dd7-9705-49c6b8615e23
Merge trashcan body, dropdown checkmark, and tree arrows into one sprite.

git-svn-id: http://blockly.googlecode.com/svn/trunk@1747 c400ca83-b69d-9dd7-9705-49c6b8615e23
Merge trashcan lid into sprite.

git-svn-id: http://blockly.googlecode.com/svn/trunk@1748 c400ca83-b69d-9dd7-9705-49c6b8615e23