Major update - corrected recognition of movies, sounds or image strips

Strips (MOVIE, SOUND or IMAGE) information that is shown as "Strip Data" in the Sequencer Buttons panel now display correct information regarding the strip type. With this update, output errors that were shown in the terminal (even though they did not interfere with usability) are now corrected also.

Another relevant addition is that a button "Use audio as Mono" has also been added, making panning extremely easy now with audio sources that were brought into Blender's VSE timeline and are not mono on their origin.