[0.6.4.10] 2016-06-28
    - improve "mcm --help" output
    - fix why-can-immediate-locals-not-have-underscores bug
    - fix "let =" parsing oddity
    - slightly simplify compiled mcm output
    - spelling and punctuation fixes
[0.6.4.9] 2016-06-25
    - add one further parseerrortest
    - fix long-contents-with-some-$fragments-are-slow bug