[Enter description of this extension point.]
The class that gets instantiated to represent the action
note that this parameter in none-or-one, since sub menus don't
have action
If the url is set and no class is specified then this action will
open a browser at the specified location.
If the class is specified, this parameter is ignored.
[Enter the first release in which this extension point appears.]
[Enter extension point usage example here.]
[Enter API information here.]
[Enter information about supplied implementation of this extension point.]