Created empty directory class
Updated phpdoc for method read
Created generic filesystem object interface (currently not implemented)
Updated todo and added hasContent to filesystemInterface
Created FilesystemCollection based on SplObjectStorage
Created FilesystemAbstract
Moved methods from File.php to FilesystemAbstract.php
Added "Object" to filesystem dependend classes
Added fluent interface to suitable methods
Removed "Filesystem" from Object classes
Refactored class
Removed unsuitable method
Implemented ObjectInterface
Fixed spelling in "isWritable", added "isNew" to abstract class
Moved "isReadable", "isWritable" and "isExecuable" to abstract class
Moved getContent to abstract class
Refactored objectColletion
Added attach method to collection
Updated handling with files and directories by using refactored object collection
Updated todo list