Fix some messed up indentation.
Much improve the reliability of the reused memoisations, there will be a lot less keeping of memoisations that will become invalid.  This is done by setting the divergence point to the point just before there are only core memoisations - ie the last "useful" (in terms of the main grammar) memoisation.
Add a `lowerCaseAnything` rule, which is useful for case insensitive matching.
1.0.4