VALUE ADDS:
* check has calls -- ordered and unordered
- DONE
* check exactly these calls -- ordered and unordered
- DONE
* implement ACTIONS instead of just return values
- DONE
- done as return value, function and closure overrides
* multiple return values
- DONE
* good logging / assertion failure messages
- TODO
* implement macros to generate mock boilerplate
- TODO
* implement COMMON MATCHERS for each of the call checks
- matchers used for expectation matching
- matchers used for return value deduction
- TODO