CAF::Path: add a is_symlink() function

[jouvin]

If I understood properly the documentation, there is no trivial way of assessing that an existing file or directory is a symlink with CAF::Path, something that is sometimes desirable? What about adding is_symlink() function that could be used in conjunction with other xxx_exists() function to check if an object is a symlink?

[stdweird]

adding sym/hardlink support is on the todo list. just testing is not enough, also creating a link is required and the maventools need support for the new caf methods.