Simplify matcher entries

[dehnert]

Matcher entries currently look like (fetcher, matchers, cond). However, the matchers is always [build_matcher(regexp, re.I)], and the cond is always lambda m: True or lambda m: cls in m.cls. This should just be (fetcher, regexp, cond) or so to allow for more useful introspection of the matchers. (See also #4, which this is basically part of, and #11, which this is probably a prereq for.)

[dehnert]

At the API level this is done by commit 64e9358. MatchEngine's internal storage format could be improved, though.