Various Makefile consistency cleanups:

  - make OSDIR also automatically be relative to src/ like INCDIR
  - SUBDIRS is now generated in src/Makefile only and not in
    Makefile.config because it is a local define for this location.
  - remove BROKEN_BPRINTF_FLAGS because is it no longer used inside
    any Makefile but make sure that at least the "-K inline" is kept in
    CFLAGS for SCO 5.
  - update the "depend" targets in Makefile.tmpl files to use $(OSDIR), too.
  - updated the dependencies theirself


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@81224 13f79535-47bb-0310-9956-ffa450edef68