avoid "i".to_i(36) cause 0 under tr_TR locale.
This is newly implemented, not a copy of missing/strtoul.c.
* include/ruby/ruby.h (ruby_strtoul): declared.
(STRTOUL): defined to use ruby_strtoul.
* bignum.c, pack.c, ext/socket/socket.c: use STRTOUL.
* configure.in (strtoul): don't check.
* missing/strtoul.c: removed.
* include/ruby/missing.h (strtoul): removed.
* common.mk (strtoul.o): removed.
* LEGAL (missing/strtoul.c): removed.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@14850 b2dd03c8-39d4-4d8f-98ff-823fe69b080e