Changelog for mcm-0.6.8.1

[0.6.8.1] 2018-10-25 - fix typo and improve description formatting [0.6.8.0] 2018-10-14 - implement $linn [0.6.7.1] 2018-10-13 - fix $numformat-wrong-answer-for-0 boundary bug [0.6.7.0] 2018-10-13 - basic $numformat implementation [0.6.6.0] 2017-08-29 - distinguish between non/empty directories in MCM's displayed output - make it easier still to run the tests on preexisting binaries [0.6.5.0] 2017-01-09 - enable mcmtags to generate qualified tags (e.g. Admin.Packages.add) - enhance mcm.vim to make use of qualified tags [0.6.4.12] 2016-11-29 - clean up emission of parse errors - permit use of @SPACE and other uppercase constants in package lets [0.6.4.10] 2016-06-28 - improve "mcm --help" output - fix why-can-immediate-locals-not-have-underscores bug - fix "let =" parsing oddity - slightly simplify compiled mcm output - spelling and punctuation fixes [0.6.4.9] 2016-06-25 - add one further parseerrortest - fix long-contents-with-some-$fragments-are-slow bug