* Can get all data of Properties structures by getDataMap(), which
return a MetadatasMap.
* Update Print file. This is the choice of the application which uses
AvTranscoder of how to display the data.

Easier to parse.

* Use the typedef as ofter as possible.
* This structure will enable us to give the data with the order we want
(which is not the alphabetic order).

Update order of data for:
   * VideoProperties.
   * AudioProperties.
   * Properties.

* This functions fills metadata parameter with the given AVDictionary.
* Use it when add metadata of AVFormatContext in InputFile::analyse
function.

* All type of stream can have metadata!
* Fill these data when add metadata of AVFormatContext of the stream in
InputFile::analyse function.
* Get these data with getDataMap function corresponding to the structure
you want.