Merged changes from /trunk/echam-dev

* r3359: Script generation: improved documentation (README, user guide), fixed time limits, number of tasks override
* r3358: Downgraded automake use to 1.13.1 installed as module in squeeze.
* r3357: J.S.Rast: Added missing profile viewgraphs.

mkexp

@@ -276,8 +276,9 @@ for subjob, subconfig in config['jobs'].iteritems():
 
         # Add useful settings
         subconfig['id'] = subjob
-        subconfig['tasks'] = int(subconfig.get('nodes', 1)) * \
-                             int(subconfig.get('tasks_per_node', 1))
+        if not 'tasks' in subconfig:
+            subconfig['tasks'] = int(subconfig.get('nodes', 1)) * \
+                                 int(subconfig.get('tasks_per_node', 1))
 
         # Check namelist override
         config_lines.seek(0)