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/glibc-bootstrap-system.patch

@@ -0,0 +1,28 @@
+We want to allow builds in chroots that lack /bin/sh.  Thus, system(3)
+and popen(3) need to be tweaked to use the right shell.  For the bootstrap
+glibc, we just use whatever `sh' can be found in $PATH.  The final glibc
+instead uses the hard-coded absolute file name of `bash'.
+
+--- a/sysdeps/posix/system.c
++++ b/sysdeps/posix/system.c
+@@ -134,7 +134,7 @@ do_system (const char *line)
+       INIT_LOCK ();
+ 
+       /* Exec the shell.  */
+-      (void) __execve (SHELL_PATH, (char *const *) new_argv, __environ);
++      (void) __execvpe (SHELL_NAME, (char *const *) new_argv, __environ);
+       _exit (127);
+     }
+   else if (pid < (pid_t) 0)
+
+--- b/libio/iopopen.c	2012-06-30 21:12:34.000000000 +0200
++++ b/libio/iopopen.c	2012-12-19 12:52:29.000000000 +0100
+@@ -226,7 +226,7 @@ _IO_new_proc_open (fp, command, mode)
+ 	    _IO_close (fd);
+ 	}
+ 
+-      _IO_execl ("/bin/sh", "sh", "-c", command, (char *) 0);
++      execlp ("sh", "sh", "-c", command, (char *) 0);
+       _IO__exit (127);
+     }
+   _IO_close (child_end);