Make rake jasmine:ci run specs correctly.

- Will replace rake core_specs.
- Remove obsolete dependencies & files -- most of these were for build tasks we
  are no longer using. Notably, rspec and spec_helper were deleted.

spec/javascripts/core/ExceptionFormatterSpec.js

@@ -0,0 +1,56 @@
+describe("ExceptionFormatter", function() {
+  describe("#message", function() {
+    it('formats Firefox exception messages', function() {
+      var sampleFirefoxException = {
+          fileName: 'foo.js',
+          lineNumber: '1978',
+          message: 'you got your foo in my bar',
+          name: 'A Classic Mistake'
+        },
+        exceptionFormatter = new j$.ExceptionFormatter(),
+        message = exceptionFormatter.message(sampleFirefoxException);
+
+      expect(message).toEqual('A Classic Mistake: you got your foo in my bar in foo.js (line 1978)');
+    });
+
+    it('formats Webkit exception messages', function() {
+      var sampleWebkitException = {
+          sourceURL: 'foo.js',
+          line: '1978',
+          message: 'you got your foo in my bar',
+          name: 'A Classic Mistake'
+        },
+        exceptionFormatter = new j$.ExceptionFormatter(),
+        message = exceptionFormatter.message(sampleWebkitException);
+
+      expect(message).toEqual('A Classic Mistake: you got your foo in my bar in foo.js (line 1978)');
+    });
+
+    it('formats V8 exception messages', function() {
+      var sampleV8 = {
+          message: 'you got your foo in my bar',
+          name: 'A Classic Mistake'
+        },
+        exceptionFormatter = new j$.ExceptionFormatter(),
+        message = exceptionFormatter.message(sampleV8);
+
+      expect(message).toEqual('A Classic Mistake: you got your foo in my bar');
+
+    });
+  });
+
+  describe("#stack", function() {
+    it("formats stack traces from Webkit, Firefox, node.js or IE10+", function() {
+      if (jasmine.getEnv().ieVersion < 10 || jasmine.getEnv().safariVersion < 6) { return; }
+
+      var error;
+      try { throw new Error("an error") } catch(e) { error = e; }
+
+      expect(new j$.ExceptionFormatter().stack(error)).toMatch(/ExceptionFormatterSpec\.js.*\d+/)
+    });
+
+    it("returns null if no Error provided", function() {
+      expect(new j$.ExceptionFormatter().stack()).toBeNull();
+    });
+  });
+});