imv (image viewer for X and/or Wayland)

imv is a command line image viewer intended for use with tiling window
managers. Features:

* Native Wayland [2] and X11 [1] support
* Support for dozens of image formats including:
  * PNG [1]
  * JPEG [1]
  * Animated GIFs [3]
  * SVG [4]
  * TIFF [1]
  * Various RAW formats [5]
  * Photoshop PSD files [5]
* Configurable key bindings and behaviour
* Highly scriptable with IPC via imv-msg

Optional dependencies (autodetected):

- FreeImage (support for GIF, RAW, PSD formats)
- libnsgif (support for GIF)

If you don't have at least one of FreeImage or libnsgif, imv won't
support GIF images at all.

Notes:

[1] - uses a library from core Slackware, so always enabled.
[2] - requires either FreeImage or libnsgif.
[3] - imv supports SVG images, but the librsvg in Slackware 14.2 is too
      old for imv to use, so SVG support is disabled. Sorry.
[4] - requires FreeImage.