We don't need to load the file twice just to get the
dimensions. We can load a GdkTexture, use it's APIs
for the width and height, and return that as a result
to the window. This allows us to kill the `dimensions-loaded`
signal and one of the places where we need to load a file.
Simplifies our action handling a lot - we no longer need
to use the `action!` macro here, and we don't need
`lookup_action ()` to set the action state or activate
actions.
This commit adds directory navigation to Image Viewer.
Currently it only sorts images by name, instead of following
directory sorting like the mockups.
The initial commit of gnome-image-viewer.
Things are in an MVP state, with image viewing and
opening from the desktop functional. We also can
open images externally, print them, and set them as
backgrounds.
