See http://marc.info/?l=graphviz-devel&m=
129418103126092 for the
motivation (basically, some word processor now uses *.dot).
* doc/figs/example-reduce.dot: Rename as...
* doc/figs/example-reduce.gv: this.
* doc/figs/example-shift.dot: Rename as...
* doc/figs/example-shift.gv: this.
* doc/figs/example.dot: Rename as...
* doc/figs/example.gv: this.
* doc/local.mk: Adjust.