hal_lib.c:  silence 'implicit declaration' compiler warning
WIP:  Get this thing running

- Script fixes
- Fix rtlib directory
- Don't automatically rerun configure
- Detect flavor from environment in rtapi_compat default_flavor()
  - FIXME:  is this correct?
- Dumbly remove 'hack around' code in rtapi_compat default_flavor()
  - FIXME:  needs attention
  - FIXME:  see FIXME note in code