distro: Change the module name space to (gnu ...).

* distro: Rename to...
* gnu: ... this.  Update module names accordingly.
* Makefile.am: Adjust accordingly.
* po/POTFILES.in: Likewise.
* distro.scm: Search for files under /gnu/packages instead of
  /distro/packages.
* gnu/packages/base.scm (ld-wrapper-boot3): Likewise.

gnu/packages/patches/make-impure-dirs.patch

@@ -0,0 +1,40 @@
+Purity: don't look for library dependencies (of the form `-lfoo') in
+/lib and /usr/lib.  Likewise, when searching for included Makefiles,
+don't look in /usr/include and friends.
+
+Patch from Nixpkgs, by Eelco Dolstra.
+
+diff -rc make-3.81-orig/read.c make-3.81/read.c
+*** make-3.81-orig/read.c	2006-03-17 15:24:20.000000000 +0100
+--- make-3.81/read.c	2007-05-24 17:16:31.000000000 +0200
+***************
+*** 99,107 ****
+--- 99,109 ----
+  #endif
+      INCLUDEDIR,
+  #ifndef _AMIGA
++ #if 0    
+      "/usr/gnu/include",
+      "/usr/local/include",
+      "/usr/include",
++ #endif    
+  #endif
+      0
+    };
+diff -rc make-3.81-orig/remake.c make-3.81/remake.c
+*** make-3.81-orig/remake.c	2006-03-20 03:36:37.000000000 +0100
+--- make-3.81/remake.c	2007-05-24 17:06:54.000000000 +0200
+***************
+*** 1452,1460 ****
+--- 1452,1462 ----
+    static char *dirs[] =
+      {
+  #ifndef _AMIGA
++ #if 0
+        "/lib",
+        "/usr/lib",
+  #endif
++ #endif
+  #if defined(WINDOWS32) && !defined(LIBDIR)
+  /*
+   * This is completely up to the user at product install time. Just define