ProgressListener: separate interface from implementation

* Create ProgressListener.cpp.
* Add include to iostream in Transcoder.
Add progress folder

* Contains all files related to the progress.
* Also contains corresponding swig interface file.
Progress: split into one class per file

* 3 classes / files: IProgress, ConsoleProgress, NoDisplayProgress.
* Add a cpp file just for ConsoleProgress (the implementation is more
'complicated' than the others).