Make readability/check More Configurable #275

Currently, the check macro names are hard coded to names found in such libraries as glog. It would be nice if they could be renamed to support other libraries. For example, some might prefer to customize the macro name and functionality. Some example names are ones that are fully spelled out: EQUAL, NOT_EQUAL, GREATER_THAN_OR_EQUAL, etc.

What would be the best way to configure this?