* configure.in (target configurations): Reformat into table.

* configure.in (target configurations):  Reformat into table.
Remove unsupp. Amigados host and target.  Ditto Mach 386 target.

* tm-altosgas.h, tm-i386v-g.h:  Remove ancient coff encap configs.
* config/{altosgas.mt, i386v-g.mt, i386v32-g.mt}:  Ditto.
* config/{i386sco.mt,i386v32.mt}:  Remove; identical to i386v.mt.
* config/{go32.mt,i960.mt}:  Remove; they only printed error msgs.
* config/nindy960.mt:  Remove useless MT_CFLAGS setting.
* config/i386aout.mt:  Use tm-i386v.h, not tm-i386v-g.h.

* Makefile.in (config-check):  Add command to check whether
configure.in is consistent with config/*.