guide:DEBUG=fasle in coffee
res:dock:: fix appid problem.

change _ to -.
res:dock:: fix drag problem.

if there is no docked items, there is no item can be dragged to dock.

reason:
not handler that.
res:dock:: fix blank problem.

the set wrong side for dragging blank.
res:dock:: fix region problem.

not update region on item is added/removed.