[Bug] Filmstrip can't be downsized

[aurelienpierre]

Due to children using gtk_wiget_set_size_request (which sets the mimimum acceptable size), the filmstrip can only be upsized, though the content of GtkBin is supposed to follow its parent size.

[sahlirc]

I just looked at the filmstrip in the darkroom version 1764 using a 27" display. I find the size of the thumbnails very small as default and appreciate that one can upsize them, and that the behavior of filmstrip resizing has improved compared to previous versions.