On workboards, provide all of the supported "create task" forms in the dropdown

Summary:
Ref T12314. Ref T6064. Ref T11580. If an install defines several different task create forms (like "Create Plant" and "Create Animal"), allow any of them to be created directly onto a workboard column.

This is just a general consistency improvement that makes Custom Forms and Workboards work together a bit better. We might do something fancier eventually for T6064 (which wants fewer clicks) and/or T11580 (which wants per-workboard control over forms or defaults).

Test Plan:
  - Created several different types of tasks directly onto a workboard.
  - Faked just one create form, saw the UI unchanged (except that it respects any renaming).

{F3492928}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12314, T11580, T6064

Differential Revision: https://secure.phabricator.com/D17446

webroot/rsrc/js/application/projects/WorkboardController.js

@@ -21,7 +21,6 @@ JX.install('WorkboardController', {
     uploadURI: null,
     coverURI: null,
     moveURI: null,
-    createURI: null,
     chunkThreshold: null
   },
 
@@ -170,7 +169,7 @@ JX.install('WorkboardController', {
         order: board.getOrder()
       };
 
-      new JX.Workflow(this.getCreateURI(), request_data)
+      new JX.Workflow(column_data.createURI, request_data)
         .setHandler(JX.bind(board, board.updateCard))
         .start();
     },