Ability to minimize the widget-item

[RezaRahmati]

Select one ... (check one with "x")

[ ] bug
[x] feature request
[ ] enhancement

As a user I want to be able to mimimize a widget and pull other widget-items up if there is enough space

Expected behavior

Actual behavior

Reproduction of behavior

• Include a link to the reproduction scenario you created by forking the Ngx-widget-grid Plunker Templates:

Environment details

• Angular version: 4.1.x

• OS and version:

• Browser: [all | Chrome XX | Firefox XX | IE XX]