Fixed build errors and unit tests fail

Updated project files in order to fix build errors (added link to UIKit and CoreGraphics frameworks). Fixed unit tests fail - XCTAssertEqual validates the arguments types. Added explicit type cast.
I got the liker errors while building the `OCMockLibTests` target:

Undefined symbols for architecture i386:
  "_CGRectEqualToRect", referenced from:
      -[OCMockObjectPartialMocksTests testCallsToSelfInRealObjectStructReturnAreShadowedByPartialMock] in OCMockObjectPartialMocksTests.o
  "_CGRectZero", referenced from:
      -[OCMockObjectPartialMocksTests testCallsToSelfInRealObjectStructReturnAreShadowedByPartialMock] in OCMockObjectPartialMocksTests.o