Use File#expand_path for require's in script/* for Ruby 1.9.2 compatibility. #4050

Use File#expand_path for require's in script/* for Ruby 1.9.2 compatibility. #4050

Since Ruby 1.9.2, LOAD_PATH does not include "." directory anymore, so
we should use absolute paths instead to ensure both 1.8.x and 1.9.x
compatibility. It has been included in railties 2.3.x branch since
july 2009, see http://github.com/rails/rails/commit/7a427a83ca4da92c70760007aaf313638a5d8374

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@4359 e93f8b46-1217-0410-a6f0-8f06a7374b81