be located in this directory.  dir/file name convention;
    test/{module_name}/test_{testcase_name}.rb
    test/{module_name}/{needed_files}
  someday, someone will write testrunner which searches test_*.rb and
  run testcases automatically

* test/csv/*: add testcase for lib/csv.rb.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4484 b2dd03c8-39d4-4d8f-98ff-823fe69b080e