Added additional file operations
Added optional constructor's parameter
Finished the 'FileUpload' class
Made the file input 'required'
Made some changes with filenames of objects
Made an auto-file-naming algorithm for uploaded files
Removed 'final' class context, added $is_debugmode in constructor & added method `Exists()`
Added directory value for uploaded files
removed appending of file extensions when using original filenames
Fixed rendered filenames for non-appended extensions
Removed 'final' class context
Finished upload module
Added method `RemoveSpaces()`
Now working on the task submission entries