Makefile:  remove left over RTDIR_INC reference
remove obsolete PTH_CONFIG variable
Remove last reference to RTNAME
configure.in:  always build drivers, even for posix
WIP:  separate rtlib for universal build

- OBJDIR, DEPDIR, RTLIBDIR flavor-specific output directories in Makefile
  - ../rtlib -> $(RTLIBDIR)
  - objects/rt -> $(OBJDIR)/
  - depends/rt -> $(DEPDIR)/
- hal/components/Submakefile
  - "You are in a maze of twisty little passages, all alike"
  - *.comps -> *.c files go into halcomp-srcs
    - putting them into hal/components/*.c creates a .gitignore nightmare
  - fix other rules to play along

FIXME:  running is broken:
  MSGD:0 ERROR: gave up waiting for rtapi_app to become ready