Remove show and hide functions.

Jquery object does have this function anyway.
Add dragg contstraint.

Packery has some strange behaviours when the user drags the elements
outside the layout wrapper. So the constraint prevents the user from
dragging the elements outside this wrapper. Furthermore it's more
controllable where the items is dropped. The pointer cursor is just for
indicating the user is in an interaction with the item.
Move the gutter and duration in config file.

Transitionduration is user more than once in the layoutmanager so the
value can be changed one time in the config file.
Refactor fixPosition function

The layoutmanager now detects when the position has to be fixed. This
improvment causes less triggers for layouting. So the elements get
arranged one time when an item has dropped.
Change y component of grid.
Codeprettifying
Add border and counter to item.
Add pointer cursor and interaction indicator.

The orange background color indicates an interaction with the toolbox
components as well as the pointer cursor.