win32/configure.bat: option arguments

* win32/configure.bat: try to fix option arguments split by commas and
  equals here.  this batch file no longer run with old command.com.
* tool/mkconfig.rb: no hacks for cmd.exe.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40019 b2dd03c8-39d4-4d8f-98ff-823fe69b080e