Squashed spy refactor and new spy syntax

Jasmine spies now have a 'and' property which allows the user to
change the spy's execution strategy-- such as '.and.callReturn(4)'
and a 'calls' property which allows inspection of the calls a spy
has received.

* This is a breaking change *

There is a CallTracker that keeps track of all calls and arguments
and a SpyStrategy which determines what the spy should do when it
is called.

spec/core/SpyStrategySpec.js

@@ -0,0 +1,82 @@
+describe("SpyStrategy", function() {
+
+  it("defaults its name to unknown", function() {
+    var spyStrategy = new j$.SpyStrategy();
+
+    expect(spyStrategy.identity()).toEqual("unknown");
+  });
+
+  it("takes a name", function() {
+    var spyStrategy = new j$.SpyStrategy({name: "foo"});
+
+    expect(spyStrategy.identity()).toEqual("foo");
+  });
+
+  it("stubs an original function, if provided", function() {
+    var originalFn = jasmine.createSpy("original"),
+        spyStrategy = new j$.SpyStrategy({fn: originalFn});
+
+    spyStrategy.exec();
+
+    expect(originalFn).not.toHaveBeenCalled();
+  });
+
+  it("allows an original function to be called, passed through the params and returns it's value", function() {
+    var originalFn = jasmine.createSpy("original").and.callReturn(42),
+        spyStrategy = new j$.SpyStrategy({fn: originalFn}),
+        returnValue;
+
+    spyStrategy.callThrough();
+    returnValue = spyStrategy.exec("foo");
+
+    expect(originalFn).toHaveBeenCalled();
+    expect(originalFn.calls.mostRecent().args).toEqual(["foo"]);
+    expect(returnValue).toEqual(42);
+  });
+
+  it("can return a specified value when executed", function() {
+    var originalFn = jasmine.createSpy("original"),
+        spyStrategy = new j$.SpyStrategy({fn: originalFn}),
+        returnValue;
+
+    spyStrategy.callReturn(17);
+    returnValue = spyStrategy.exec();
+
+    expect(originalFn).not.toHaveBeenCalled();
+    expect(returnValue).toEqual(17);
+  });
+
+  it("allows an exception to be thrown when executed", function() {
+    var originalFn = jasmine.createSpy("original"),
+        spyStrategy = new j$.SpyStrategy({fn: originalFn});
+
+    spyStrategy.callThrow("bar");
+
+    expect(function() { spyStrategy.exec(); }).toThrow("bar");
+    expect(originalFn).not.toHaveBeenCalled();
+  });
+
+  it("allows a fake function to be called instead", function() {
+    var originalFn = jasmine.createSpy("original"),
+        fakeFn = jasmine.createSpy("fake").and.callReturn(67),
+        spyStrategy = new j$.SpyStrategy({fn: originalFn}),
+        returnValue;
+
+    spyStrategy.callFake(fakeFn);
+    returnValue = spyStrategy.exec();
+
+    expect(originalFn).not.toHaveBeenCalled();
+    expect(returnValue).toEqual(67);
+  });
+
+  it("returns the spy after changing the strategy", function(){
+    var spy = {},
+        spyFn = jasmine.createSpy('spyFn').and.callReturn(spy),
+        spyStrategy = new j$.SpyStrategy({getSpy: spyFn});
+
+    expect(spyStrategy.callThrough()).toBe(spy);
+    expect(spyStrategy.callReturn()).toBe(spy);
+    expect(spyStrategy.callThrow()).toBe(spy);
+    expect(spyStrategy.callFake()).toBe(spy);
+  });
+});