- the basic image now contains a minimal listener
- new repl.c uses the embedded listener rather than
implementing the listener in C
- removed barebones.c as it's no longer needed (overlapped
w/repl.c)
- removed retro-unix.c (use retro.c instead)
- removed retro-windows.c (use retro.c instead)
- removed retro-image.c (use image.c instead)
FossilOrigin-Name: 21cea9bf556aef732fd9248de2debaf00dce24304a426c56392d503723728f43