when makefiles are modified.
* {bcc32,win32,wince}/Makefile.sub (config.status): add variables
for tests.
* win32/ifchange.bat: try to update a file only if modified.
* win32/resource.rb: more descriptions.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@8057 b2dd03c8-39d4-4d8f-98ff-823fe69b080e