Bug fixes:
- GH #271, GH #164 - Detect undefined command in arrayref at harness parse
time instead of deferring to start() (PR #272)
- pipe_writer drops input when data is the string "0" due to redundant
boolean test on input buffer (PR #264)
- Callback filter evaluates return in list context to distinguish empty
return from the string "0", preventing infinite loop on Win32 (PR #264)
- GH #240 - Skip pty output assertions on BSD/Darwin due to known pty
drain timing issues on short-lived children (PR #274)
- Implement proper Windows command-line parsing per Microsoft C/C++ rules,
fixing argument parsing failures with single-quoted strings containing
whitespace (PR #273)
Maintenance:
- Add shebang to eg/synopsis_scripting (PR #275)