Unify status for xdescribe and xit

- Ensure *All's only execute if at least one child will run
- Specs will report a status of `excluded` instead of disabled

[finishes #153967580]
- #1418

Signed-off-by: Elenore Bastian <ebastian@pivotal.io>

spec/core/JsApiReporterSpec.js

@@ -192,7 +192,7 @@ describe("JsApiReporter", function() {
       };
       suiteResult2 = {
         id: 2,
-        status: 'finished'
+        status: 'passed'
       };
 
       reporter.suiteStarted(suiteStarted1);