Item2141: add a USERLIST macro for admins

Bulk rego, bulk password reset and the UserAdmin UI all need a way to get the list of users.

I'm going to add code to the HTTPDUserAdminContrib to do it initially, but would like to consider adding it to the core for 1.1

-- SvenDowideit - 23 Sep 2009

This would need a feature proposal to add the extension as a default extension.

Removing the Engine component of this.

-- GeorgeClark - 07 Jan 2015