MFH: r402380

x11-wm/openbox: fix dependencies and default package

At build time openbox tries to detect presence of some
X11 extentions libs and headers and silently disables
support for them if they cannot be found.

When building from port, these extensions are usually
available already, so user gets a fully functional package,
however, when installing from package user gets a package with
a limited functionality.

Fix this by adding all the required dependencies to USE_XORG.

PR: 204706
Approved by: portmgr (erwin)