The regular expression stuff needs some of a rethink.

Things that could be made more efficient, as I think of them:

(1) Making Arrays in Wrap* may be a bit inefficient
counter: Usage may be like "look up element 3" so random access is good

(2) String DFA: the findRegex computes the prefix string itself, which is sometimes wasted / sometimes wanted / always discarded.  Also, the input string at the start of the match is discarded

(3) Lazy computes MatchedStrings array then discards it.  Wasteful.

(4) Mighty extend RegexLike with ability to return "strings", i.e. Extract instance.  The default conversion could be left in for some things.   Then RegexContext could pull from that instead of matchOnce/matchAll.

(5) make RegexLike default matchAll/matchOnce in terms of matchOnceText and matchAllText
