Log message:
 * Need pkg-config to build.  Noticed by Hasso Tepper in PR 38918.
 * Not using glib, but ckeck it in configure, put fake glib.pc.
 * No need custom do-install target. change to normal install and post-install.
 * Add DESTDIR support.

Log message:
Fluxbox Tray Menu

If you want a fast way to reach your Fluxbox menus when you're using all
your screen, your problems are over.

Now you can use the Fluxbox Tray Menu to put a icon on your toolbar, and
when clicking with the left button, your Fluxbox menus will appear!