gnu: Rename (gnu packages system) to (gnu packages admin).

* gnu/packages/system.scm: Rename to...
* gnu/packages/admin.scm: ... this.  Adjust module name accordingly.
* gnu-system.am (GNU_SYSTEM_MODULES): Update.

gnu-system.am

@@ -25,6 +25,7 @@ GNU_SYSTEM_MODULES =				\
   gnu/packages.scm				\
   gnu/packages/acct.scm				\
   gnu/packages/acl.scm				\
+  gnu/packages/admin.scm			\
   gnu/packages/algebra.scm			\
   gnu/packages/apl.scm				\
   gnu/packages/apr.scm				\
@@ -181,7 +182,6 @@ GNU_SYSTEM_MODULES =				\
   gnu/packages/sqlite.scm			\
   gnu/packages/ssh.scm				\
   gnu/packages/swig.scm				\
-  gnu/packages/system.scm			\
   gnu/packages/tcl.scm				\
   gnu/packages/tcsh.scm				\
   gnu/packages/texinfo.scm			\

gnu/packages/admin.scm

@@ -17,7 +17,7 @@
 ;;; You should have received a copy of the GNU General Public License
 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
 
-(define-module (gnu packages system)
+(define-module (gnu packages admin)
   #:use-module (guix licenses)
   #:use-module (guix packages)
   #:use-module (guix download)