core_ex 0.5.5.0

CoreEx is designed to provide a simple but quite useful extension of the standard library of Ruby. So some classes and modules like Pathname, Time, Enumerable, Exception, FileUtils, String, and YAML are extended. There is also some new features like attr_once, DTime, TempPath, Version, embedded_tests, filelist (almost from rake), a common Rakefile, and an extension of the require system.