add some more old files from the 1990s

also:
- make some more makefiles respect @datarootdir@
- update changelog
- minor configure tweaks
- fix some arch-specific stuff for gdbserver
- silence some warnings in nindy-share now that I have a (somewhat old,
but working) Makefile for that subdir
- use autoheader for src/gdb/nlm
- fix some makefiles that would ignore archflags
- readline: properly clean up after a shlib build, and stop using the
`-v` flag when compiling (it just prints the version of gcc, which
makes output harder to read)
- src/sim: avoid using -Wuninitialized without optimization
- src/sim/testsuite: actually use maintainer mode
- src/tcl/unix/dltest is messed up, so mess it up even more (Now TWO
separate configure scripts try to AM_INIT_AUTOMAKE its Makefile.am!)