graphics/ximaging: New port: Image Viewer and Browser for Unix/X11

This port is an image viewer/browser that use the Motif toolkit, it is
developed by the same developer of x11-wm/emwm, therefore it is well
integrated with it but work great in any graphical environment. The
compatibility with others architectures than amd64 is probable but not
tested - written in C ANSI.

PR: 280734