Fixes: ArcticaProject/nx-libs#432

debian/copyright: Update copyright attributions (re-add nx-X11/programs/Xserver/hw/nxagent/NXpicturestr_PictSolidFill.h).

Attributes GH PR #437: https://github.com/ArcticaProject/nx-libs/pull/437

Xserver/Imakefile: Drop redundant library path option -L../../../nx-X11/exports/lib when linking nxagent. As -L../../exports/lib is already present and points to the same location.

Xserver/Imakefile: Change order of linker options, so that self-built components get mentioned first in the nxagent linker command.

Attributes GH PR #436: https://github.com/ArcticaProject/nx-libs/pull/436

 Fixes ArcticaProject/nx-libs#370.

 Fixes ArcticaProject/nx-libs#383.

 This reverts commit 6c8c9502.

 Fixes ArcticaProject/nx-libs#433.

 This patch is still a candidate for being re-implemented without extending the
 _PictSolidFill struct, but for now, we'll have to re-introduce commit db8705
 for the sake of having fonts readable after resumption of remote NX sessions.

Attributes GH PR #419: https://github.com/ArcticaProject/nx-libs/pull/419

Xserver/os/connection.c: If -displayfd and an explicit display port number are given, use the explicit display number as a starting point for auto-detecting the next available display number.

Xserver/os/connection.c: Accompany display number with some human-readable (machine-parseable) text when -displayfd is set to STDERR.

Attributes GH PR #431: https://github.com/ArcticaProject/nx-libs/pull/431

"nx-X11 Agent" looks and sounds ugly.

Attributes GH PR #434: https://github.com/ArcticaProject/nx-libs/pull/434

nx-libs.spec: sync up RPM builds after Xext proto change in a51cb945.

debian/{rules,nx-x11proto-xext-dev}: More Xext header files belong int nx-x11proto-xext-dev (instead of removing them in debian/rules).

debian/control: Pull-over latest changes on these files from the official Debian package. Various improvements several package descriptions.

Attributes GH PR #421: https://github.com/ArcticaProject/nx-libs/pull/421

 Fixes ArcticaProject/nx-libs#80

Attributes GH PR #428: https://github.com/ArcticaProject/nx-libs/pull/428