Docs: Update for nsgtk3 rename.

docs/PACKAGING-GTK

@@ -29,11 +29,8 @@
   checkouts smaller and making sure changes to one set of resources updates
   the other.
 
-  The binary that the build system produces is called "nsgtk".  There is also
-  a shell script called "netsurf" that will set up the environment and launch
-  the nsgtk binary.  Do not ship this shell script with your package.  It is
-  included only as a convience for launching NetSurf from the build tree.
-  Instead, you should move nsgtk to /usr/bin/netsurf (or wherever your
+  The binary that the build system produces is called "nsgtk3".
+  You should install nsgtk3 to `/usr/bin/netsurf` (or wherever your
   distribution's packaging policy suggests) and copy the contents of
   gtk/res/ (dereferencing the symlinks, obviously) to /usr/share/netsurf (or
   wherever your packaging policy suggests).

docs/building-GTK.md

@@ -171,13 +171,10 @@ below. Or turn off the complaining features in a Makefile.config
 file. You may need to "make clean" before attempting to build after
 installing the dependencies.
 
-Run NetSurf by executing the "test-nsgtk" shell script:
+Run NetSurf by executing "nsgtk3":
 
-    $ ./test-nsgtk
+    $ ./nsgtk3
 
-This script makes it easy to run the nsgtk binary from the build tree. It
-sets up some environment variables which enable NetSurf to find its
-resources.
 
 ### Builtin resources
 

docs/quick-start.md

@@ -77,7 +77,7 @@ To build the native front end (the GTK front end on Linux, BSDs, etc)
   you could do:
 
       $ make
-      $ ./nsgtk
+      $ ./nsgtk3
 
 To build the framebuffer front end, you could do: