droppable tolarance is set to 'pointer'
droppable tolarance is set to 'pointer'

http://api.jqueryui.com/droppable/#option-tolerance
"pointer": Mouse pointer overlaps the droppable.

Former-commit-id: 8e93c670ed0d775aaa70dfe1c5b7be82ae4c54c2
webgme/webgme-engine,webgme/webgme-engine,webgme/webgme-engine