lr.default-reductions: rename "all" value to "full".

States that shift the error token do not have default reductions,
and GLR disables some default reductions, so "all" was a misnomer.
* doc/bison.texinfo (%define Summary): Update.
(Default Reductions): Update.
* src/print.c (print_reductions): Update.
* src/reader.c (prepare_percent_define_front_end_variables):
Update.
* src/tables.c (action_row): Update.
* tests/input.at (%define enum variables): Update.
* tests/reduce.at (%define lr.default-reductions): Update.