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/matchers/toBeNullSpec.js

@@ -0,0 +1,17 @@
+describe("toBeNull", function() {
+  it("passes for null", function() {
+    var matcher = j$.matchers.toBeNull(),
+      result;
+
+    result = matcher.compare(null);
+    expect(result.pass).toBe(true);
+  });
+
+  it("fails for non-null", function() {
+    var matcher = j$.matchers.toBeNull(),
+      result;
+
+    result = matcher.compare('foo');
+    expect(result.pass).toBe(false);
+  });
+});