aux/goodsh.sh: rename functions for ksh93 bug compatibility
aux/goodsh.sh: rename functions for ksh93 bug compatibility

lib/modernish/aux/goodsh.sh:
- Apparently, the way functions are defined, used, and/or unset in
  this dot script triggers a bug in ksh93 that breaks use of other
  functions defined under the same name (i.e.: _Msh_testFn later on
  in bin/modernish init). As ksh93 is quite dead, extremely buggy
  and tracing its bugs properly is akin to black magic, I can't be
  bothered: simply renaming the functions in goodsh.sh fixed it.

modernish/modernish