Log Message:
Update to 6.8.1. From the changelog:

- Fix build on musl-libc platforms (#49)
- Default CFLAGS of -g -O2 if user didn't specify any
- Fix a bug on Linux systems (#48)
- Add an OKSH_VERSION variable that gives the user the oksh version
  (KSH_VERSION and SH_VERSION are still their original values)
- Default to ST_MTIM when using --no-thanks
- Allow some code to be commented out when not compiling with curses