+gulp, +boolean, +sibling, +listview item, show/hide widget, set by association

Merged the additions of Tieniber:

+gulp, +boolean, +sibling, +listview item, show/hide widget, set by association

Small fix for Test Project

Fixed the Test Project based on Melvin's issue.

Release 1.1: restyled the code

The code in the widget was restyled.

Initial release of EnumClass

This is the first release of the EnumClass widget and allows Mendix developers to define an element's class based on an attribute value.