Optimise handler

Now being cached:
 - If allow param is an array (also using Array.isArray now)
 - Length of array for the relevant method
 - Allow regex for the relevant method

Also added a couple more tests to ensure that different methods were
being correctly handled (passed before and after)
Rename tests
Add passthroughErrors option

If true, NON GRANT errors will be passed through so you can ensure
a consistent error format with the rest of your api
v 1.3