allow eVar report permissions to be specified in group management

[#1]

In the group management, you can specify what report(s) the group has access to.  You can specify access for individual events, props, hier vars, other built in metrics, reports, etc.. basically literally everything - except eVars?  Why not eVars? It's not exposed in the Permissions API either (e.g. listed in Permissions.GetGroup  response).  Can this please be added? 

[#2]

Implemented as of 20 October 2016.