(chicken irregex): Use condition kinds

[Zipheir]

The (chicken irregex) module should raise conditions with kinds. It's hard to handle exceptions automatically without them. For example, 'irregex' raises an exception when called with a syntactically-invalid regular expression or with an object of the wrong type (say, a vector). The only way to tell which of these problems occurred is through a nasty kluge: examining the condition's message. It should instead raise a condition with kind '(exn type)' for the type error (like the rest of CHICKEN's core forms) and with kind '(exn irregex)' (e.g.) for the regular expression syntax error.