factor-lang: 0.97 -> 0.98

Much improved build with support for GUI libraries and FUEL, the emacs
development environment.

Also directs the work vocabulary to point to /var/lib/factor as a machine-local
writable location. So, scaffolding should work as intended, now.

pkgs/development/compilers/factor-lang/fuel-dir.patch

@@ -0,0 +1,20 @@
+diff --git a/misc/fuel/fuel-listener.el b/misc/fuel/fuel-listener.el
+index 2d1b182a75..bf2e573425 100644
+--- a/misc/fuel/fuel-listener.el
++++ b/misc/fuel/fuel-listener.el
+@@ -30,13 +30,13 @@
+   "Interacting with a Factor listener inside Emacs."
+   :group 'fuel)
+ 
+-(defcustom fuel-factor-root-dir nil
++(defcustom fuel-factor-root-dir "@fuel_factor_root_dir@"
+   "Full path to the factor root directory when starting a listener."
+   :type 'directory
+   :group 'fuel-listener)
+ 
+ ;;; Is factor.com still valid on Windows...?
+-(defcustom fuel-listener-factor-binary nil
++(defcustom fuel-listener-factor-binary "@fuel_listener_factor_binary@"
+   "Full path to the factor executable to use when starting a listener."
+   :type '(file :must-match t)
+   :group 'fuel-listener)