The normal case was to use the builtin icons. There were two cases
where the icon file was read from disk:

1) /usr/NX/share/images/nxagent.xpm was existing which normally is not
   there

2) case 2 was not true and nxagent.xpm was existing somewhere in the
   PATH (!)

(replace nxagent.xpm by x2goagent.xpm if in x2gp mode)

Scanning the path from the PATH variable for xpm files is kind of
unexpected and dangerous, too (think of automounter triggers or
invalid xpm files).

Also remove the xpm files from the distribution.

This file has been deleted, but references to it in the build remain,
causing `debuild` to fail.

This workaround/hack should not be needed any longer.

debian/patches: Add 2004_enforce-lpthread.patch. On Debian, enforce -lpthread when building nxcomp. This is a nasty work around for a missing symbols issue that needs to get addressed otherwise in later release.

debian/rules: Highly enforce --no-parallel mode while Xserver is still on imake. Can be re-parallelized after autotools conversion.

Revert "debian/rules: Avoid dh_auto_build. It adds -Oline since 11.2 which let's make choke in nx-X11/ subdir on the Makefiles target. Reason unknown."

This reverts commit 94d77e27.

This reverts commit 190e3df4.

debian/rules: Drop override_dh_clean. Makefile (et al.) removal in nx-X11/ has now been moved to the distclean target.

debian/rules: Avoid dh_auto_build. It adds -Oline since 11.2 which let's make choke in nx-X11/ subdir on the Makefiles target. Reason unknown.