We used to wait the end of the export_volume job before doing anything
else. Now, we have a timeout waiting inside a loop, so we can update the
job status by getting information from the node.

This patch comes with the commit named 'Handler to get data from the
child of a ForkedJob' in cc-node which implements the handler needed
to get the information from the job.

This patch adds a handler for the helpplugin command.

This patch comes with a patch for cc-cli and a patch for cc-node.

CCConf was waiting for a logging argument.
Two options were added to choose the user and group running the
cc-server. This was added to put the proper rights on json file if the
user and/or group are not the default ones.

With the permission of Romain Degez, CTO of Smartjog.

Signed-off-by: Sébastien Luttringer <sebastien.luttringer@smartjog.com>