Code review comment for lp:~ivanfateev/pantheon-files/fix-1380139

After discussion with some of the other developers, it has been decided to reject this branch for the following reasons:

1) It would bring in unwanted dependencies e.g. on gjs and X11
2) It is an elementary design decision not support a previewer in Files; there is little difference in time for the file to open in the default app compared to the previewer and the intention is to reduce any time difference further.

Thank you for your work; I am sorry we cannot accept it.