add getInfo for Node informations
Replace CPUTime by CPU usage in Agent
Modify the message contents when chatting
Replace CPUTime by Percent in UI (change also the message when chatting).
Add preferences for refresh CPU usage time
Added an auto refresh timer for CPU Usage
Fix #617 and Final PR for #613
Merge branch 'add-virtualmachine-cpu-usage' of https://github.com/CyrilPeponnet/Archipel into pr-618
Revert Repeat change on CPTimer for Screenshots as it is recreated in ImageDidLoad
Add a nice sentence when asking the hypervisor about nodeinfo.
Use a threaded timer to sample cputime

More accuracy is needed... for the next commit :)
Merge branch 'master' into add-virtualmachine-cpu-usage
Take sample as tuple (timestamp,cputime) to be more precise when computing

The threaded timer is not very precised in time so we must take the
timestamp when sampling cputime from domain (I could also be reused
later to have a stat database for domains).
Destroy the CPtimer once triggered, no REPEAT

The CPTimer for CPUusage will be created if there is no current timer
running. We also delete the current timer once the xmpp callback have
been sent.
Merge branch 'add-virtualmachine-cpu-usage' of https://github.com/CyrilPeponnet/Archipel into pr-618
Respect coding guidelines
Merge branch 'add-virtualmachine-cpu-usage' of https://github.com/CyrilPeponnet/Archipel into pr-618
Merge branch 'pr-618'