Add "Featured" button to AppInfo page, if permissions allow

[derrell]

It should be easy for an administrator to add an application to the "Featured" set. With the current interface, that will be able to be done from the Application Management page (once that's fully working) but I suspect a more likely place to do it is while viewing the AppInfo page for that application.

Add an RPC specifically to add or remove the "Featured" tag, ensure that the authenticate() method in MDbifCommon allows it only with a specified permission value, and when the current user has that permission, add a "Featured" checkbox to the AppInfo page which toggles the Featured tag by calling that RPC.

[derrell]

This will require:

• Adding a new RPC in MApps.js: setFeatured(appId, bFeatured) where bFeatured is a boolean which specifies whether to set the app to be featured or not
• Adding the new RPC name to the Permissions map in Constants.js
• Adding an entry to the switch statement in MDbifCommon.js authenticate() method. Clone the entry for "deleteApp".
• Add a "Featured" toggle button to the AppInfo page.