Enable operation arguments to accept special value characters

In CLI passing an argument \n to an operation strips the leading \ from the string. This can be averted by adding an extra \, \\n, but then the second \ and the n are treated as separate characters instead of a single newline character.

It would be nice if CLI could recognize these special characters and treat them as the special character. One idea might be to use something like the java.util.Formatter and expect values like %n instead of the \n. Either way really works though.