Improve help commands

[antonio]

Change the command and sub-commands doc
Currently are:

(a) current vs. (b) proposed

@@ -1 +1 @@
 DRM4G is an open platform, which is based on GridWay Metascheduler, to define,
 submit, and manage computational jobs. For additional information,
 see http://meteo.unican.es/trac/wiki/DRM4G .
 
 Usage: drm4g [ --version ] [ --help ]
              <command> [ options ] [ <args>... ]
 
 Options:
-    -h --help  Show help.
-    --version  Show version.
-    --dbg      Debug mode.
+    -h --help     Show help.
+    -v --version  Show version.
+    -d --debug    Debug mode.
 
 drm4g commands are:
    start       Start DRM4G daemon and ssh-agent
    stop        Stop DRM4G daemon and ssh-agent
    status      Check DRM4G daemon and ssh-agent
    restart     Restart DRM4G daemon
    clear       Start DRM4G daemon deleting all the jobs available on DRM4G
    conf        Configure DRM4G daemon, scheduler and logger parameters
    resource    Manage computing resources
    id          Manage reosurce identities
    host        Print information about the hosts
    job         Submit, get status and history and cancel jobs
 
 See 'drm4g <command> --help' for more information on a specific command.

[antonio]

The --debug option should be parser in the wrf4g command instead on each sub-command.

This piece of code, only should be appear at main command

if arg[ '--dbg' ] :
    logger.setLevel(logging.DEBUG)