Small Fixes

Fixed: The CD program now checks if you want to go into a directory and blocks files.
Fixed: The file rights program now comes with a small syntax description (also fixed an unrecognizable bug in the syntax error message).
Fixed: A JavaDoc issue in the MKFILE program.
More checks in MKFILE

Fixed: The MKFILE program will no longer crash if you input unpossible values.
Escaped Shell Help

Fixed: The shell help now gets escaped properly.
Delete File Program

Added: The DELFILE program for removing files from the file system.