Fix Registry class JavaDoc

Fix: The JavaDoc applied to the Registry class contains a hint to the TWL theme storage application of the class.
StringRepresentable interface

Add: The interface StringRepresentable. Instances of the implementing classes can be entirely represented by a string and converted back to normal objects without loosing any data. Also patch all classes which currently support such string conversions to use the new interface.
Fix some member JavaDoc

Fix: Resolve some JavaDoc issues classes in the .world.member packages had.
Add user password

Add: Every user object (configuration entry) has a SHA-256 hash of the user's password.
Add commons codec library for hashing

Note: The project depends on the apache commons codec library for generating hashes.
Move FileSystemModule into os package

Fix: The FileSystemModule class is moved to the .worl.comp.os package because it justs fits there better.
Remove old syscall infrastructure

Remove: Some forgotten syscall utilities.
Fix OperatingSystem JavaDoc

Fix: The JavaDoc class description for the OperatingSystem class.
Fix separator typo

Fix: Separator is now spelled correctly (was spelled seperator).
Add more file utilities

Add: The getComponents() method in FileUtils splits a global file path into a mountpoint and a local file system path.
Add: The getFile() and addFile() methods in FileUtils retrieve or add a file using a global file path. They resolve the required mounted file system using a FileSystemModule passed to them.
Remove "dropping" FunctionExecutionException handling

Fix: The FileUtils class doesn't catch and drop any unexpected FunctionExecutionExceptions.