Fixes an early release of a variable that's used in other blocks.

We discovered this during the UIGestureRecognize#recognize additions we were making. It seems that this wasn't a problem previously, but somehow our changes triggered an earlier release of the autorelease pool for the beforeEach block in this test. By retaining the window variable (and releasing in an afterEach block) rather than autoreleasing, this fixed the error.
Refactor Target fixture and use cedar spies

This seemed like a good idea, because when we initially made some changes to Target, we found that we were storing off a BOOL per method, and also potentially needed to store off a reference to the args that a method was called with. Since Cedar spies already provide us this functionality, it seemed like a bad idea to replicate it ourselves. Cedar spies are already used in a few other tests, so this doesn't seem like we're doing anything strange or unusual.
Adds a -recognize method to `UIGestureRecognizers`.

This allows the user to trigger gesture recognizers programmatically under test.