Move build-xorg to contrib as it is not a maintained component
diff --git a/BUILDING.txt b/BUILDING.txt
index 25af191..0cb830b 100644
--- a/BUILDING.txt
+++ b/BUILDING.txt
@@ -150,14 +150,14 @@
 building the more recent Xorg modules in a local directory and then building
 Xvnc such that it links against the local build of these libraries, not the X11
 libraries installed on the system.  The "build-xorg" script in the TigerVNC
-source distribution (located under unix/) automates this process.
+source distribution (located under contrib/xorg/) automates this process.
 
 The following procedure will build both the TigerVNC Viewer and a
 "legacy-friendly" version of the TigerVNC Server:
 
   cd {build_directory}
-  sh {source_directory}/unix/build-xorg init
-  sh {source_directory}/unix/build-xorg build [additional CMake flags]
+  sh {source_directory}/contrib/xorg/build-xorg init
+  sh {source_directory}/contrib/xorg/build-xorg build [additional CMake flags]
 
 build-xorg generates a version of Xvnc that has no external dependencies on the
 X11 shared libraries or any other distribution-specific shared libraries.  This
@@ -171,11 +171,11 @@
 This is convenient for testing changes that just apply to the TigerVNC source
 code.  To accomplish this, run:
 
-  sh {source_directory}/unix/build-xorg rebuild [additional make flags]
+  sh {source_directory}/contrib/xorg/build-xorg rebuild [additional make flags]
 
 For instance,
 
-  sh {source_directory}/unix/build-xorg rebuild clean
+  sh {source_directory}/contrib/xorg/build-xorg rebuild clean
 
 will clean both the Xvnc and vncviewer builds without destroying any of the
 build configuration or module dependencies.