* mpw-configure: Conditionalize more Makefile insertions,
set MAYBE_TARGET_DEFAULT for gcc, set NATDEPFILES for gdb,
delete Makefile.tem, compute target_{cpu,vendor,os}.
* mpw-config.in: Forward-include most .h files in include into
extra-include.
(readline): Don't build.
mpw-build.in (install): Install GDB.
mpw-README: Update/add helpful comments.
* mpw-configure (prefix, mpw_prefix): Handle it.
(ARCHDEFS): Add to makefile editing.
(TDEPFILES, TM_FILE, XDEPFILES, XM_FILE, NAT_FILE): Add to
makefile if defined.
(mpw-edit-prefix): Use during makefile editing.
* mpw-config.in (mmalloc, readline): Don't configure.
* mpw-build.in (thisscript): Rename to ThisScript.
Use mpw-build instead of BuildProgram everywhere.
(mmalloc, readline): Don't build.
* mpw-README: New file, basic documentation about the MPW port.
* mpw-configure: Add more things to the top of each configured
Makefile, including contents of config/mpw-mh-mpw.
* mpw-config.in (extra-include): Create this directory and fill it
with Posix-like include files when configuring.
* mpw-build.in: New file, top-level build script fragment for MPW.
* mpw-configure: New file, configure script for MPW.
* mpw-config.in: New file, config fragment for MPW.
