Update `TODO'.

TODO

@@ -41,8 +41,10 @@ Like scripts/build-remote.pl in Nix.
 * user interface
 ** Add a package.el (Emacs) back-end
 
-Unfortunately package.el is monolithic, so most likely we’d have to
-write a new one based on it, as opposed to actually using it.
+package.el is quite monolithic, but we may be able to reuse/extend
+‘package-menu-mode’ or at least ‘tabulated-list-mode’.
+
+** add guile-ncurses interface
 
 * extend <origin>
 ** add OpenPGP signatures:
@@ -82,6 +84,11 @@ create a new ‘dir’.
       ("i3" ,p3)))
 #+END_SRC
 
+
+* add ‘make-sha256-port’ binding for ‘gcry_md_write’ & co.
+
+This should make `derivation-hash' faster.
+
 * synchronize package descriptions with GSRC and/or the [[http://directory.fsf.org][FSD]]
 
 Meta-data for GNU packages, including descriptions and synopses, can be
@@ -89,11 +96,8 @@ dumped from the FSD:
 http://directory.fsf.org/wiki?title=GNU/Export&action=purge .
 We could periodically synchronize with that.
 
-* support cross-compilation
-
-Implement ‘package-cross-derivation’, and add the corresponding code in
-‘gnu-build-system’.  Then, actually bootstrap a cross-compilation
-environment–e.g., a cross-GNU environment.
+See http://lists.gnu.org/archive/html/bug-guix/2013-04/msg00120.html for info
+on how to synchronize with GSRC's descriptions.
 
 * add a guildhall build system