Import byacc-20141006.
byacc-20141006: Adjust some forgotten things on the vendor branch.

* skeleton.c is now yaccpar.c

* New file mstring.c

* Adjust README.DELETED
Merge branch 'vendor/BYACC'
yacc(1): Some local adjustments for byacc-20141006.

This also doubles the MAXTABLE size (which is configurable in 20141006
and the reason for this upgrade), because a newer iasl(8) was whining
about it.