fix(ngMock window.inject): fix collecting stack trace in PhantomJS

Add support for collecting current stack trace information in browsers
(e.g. PhantomJS) that do not automatically store the current stack trace
information in a newly created `Error` object's `stack` property, but
only add it there once the `Error` gets thrown.

The original implementation works fine in Firefox & Chrome, but fails on
PhantomJS where it, for example, breaks karma's error reporting in cases
when an exception for thrown in a test like the following:
```
it('the holy crusade', inject(function () {
  var x = {};
  x.holyGrail();
}));
```
where the ngMock `inject()` implementation would incorrectly add the word
`undefined` to the end of the collected error stack trace information,
thus causing the main error description to be reported back to karma as
`undefined`.

The whole `Error.stack` property and its behaviour is not standardized so
there is no one true implementation that we can assume is used by all
angular compatible browsers.

MSDN JavaScript `stack Property (Error) (JavaScript)` docs found at
http://msdn.microsoft.com/en-us/library/windows/apps/hh699850.aspx also
seem to match the PhantomJS implementation.

Author: jurko-gospodnetic

src/ngMock/angular-mocks.js

@@ -2899,6 +2899,15 @@ angular.mock.$RootScopeDecorator = ['$delegate', function($delegate) {
   window.inject = angular.mock.inject = function() {
     var blockFns = Array.prototype.slice.call(arguments, 0);
     var errorForStack = new Error('Declaration Location');
+    // some browsers, e.g. PhanthomJS, do not set a new error object's stack
+    // information until it has been thrown
+    if (!errorForStack.stack) {
+      try {
+        throw errorForStack;
+      } catch (e) {
+        errorForStack = e;
+      }
+    }
     return wasInjectorCreated() ? workFn.call(currentSpec) : workFn;
     /////////////////////
     function workFn() {