Extend :ERR criteria to test attributes of condition object

You can't, for example, look to see that slots of an error are filled with the 
right values.

The underlying problem is that, since condition objects aren't ''returned'', 
but caught, you can't pass the condition object to sub-criteria.

If, for example, we were to extend the `:err` check to be of the form:

`(:err [:type` ''type''`] [:criterion `''crit''`])`

and pass the condition object to the criterion expression, ''crit'', it would 
solve the problem.

Original issue reported on code.google.com by john.mar...@gmail.com on 2 Sep 2014 at 4:34

jphmrst / cl-nst

Extend :ERR criteria to test attributes of condition object #14