Add 991_fix-hr-typos.full+lite.patch and 991_fix-hr-typos.full.patch. Fix several typos in upstream code detected by lintian.

Update 600_nx-X11+nxcompext+nxcompshad_unique-libnames.full.patch. Don't patch files that get removed during code reduction.

Unify source tree reduction (debian/rules vs. roll-tarball.sh) via file/folder lists in text files named debian/CODE-REDUCTION_*.

debian/roll-tarball.sh: Install etc/ files into etc/ subfolder (rgb, nxagent.keyboard, x2goagent.keyboard).

debian/rules: Correctly link config files (etc/rgb, etc/nxagent.keyboard, etc/x2goagent.keyboard) before dh_auto_build.

Allow sysadmins to manipulate nxagent's / x2goagent's rgb file by placing it into /etc/nxagent or /etc/x2go.

Extend 999_nxagent_unbrand-nxagent-brand-x2goagent.full.patch. Allow separate .keyboard files for x2goagent and nxagent.

Extend 999_nxagent_unbrand-nxagent-brand-x2goagent.full.patch. Let rgb file shipped with x2goagent supersede rgb file shipped with nxagent. FIXME: a better approach would be to decide at runtime if to use /etc/x2go/rgb or /etc/nxagent/rgb.

  * Debian/Ubuntu packaging:
    + Fully rework the way nx-libs gets packaged for Debian/Ubuntu.
    + Split up libnx-x11 into individual packages.
    + Provide dbg:packages for each bin:package containing binaries.
    + Use Makefile logic to install files into DESTDIR.
    + Provide dev:packages for each lib:package individually.
    + Provide nx-x11proto-*-dev packages for all libnx-* libraries.
    + Install _all_ library files (*.so*) to /usr/lib/<triplet>/, so
      no extra settings of LD_LIBRARY_PATH is necessary.