in metric methods, trigger_session_update

so that socket refreshes the user instance and get_stats starts
asking for the new metrics
Add debuging flag for loging socketio info
Merge branch 'termjs' of https://github.com/mistio/mist.io into termjs
Add ping event handler
simplify some attribute names
Merge branch 'termjs' of github.com:mistio/mist.io into termjs
split ssh and ping to separate probe functions
Move socket event handling for list keys on keys controller
add current timestamp to probe-ssh result
split ping and ssh celery probing tasks
Merge branch 'termjs' of github.com:mistio/mist.io into termjs
Move backend related socket handlers from app.js
Use min vlaue only for negative min values
Merge branch 'termjs' of github.com:mistio/mist.io into termjs
fix uptime display
trigger_session_update on toggle_backend to refresh socketio user instance
Fix manual probing
get retval when sending shell commands
Try to fix some dummy graph issues
fix collectd custom python plugins conf files

using separate conf file per plugin caused unpredictable
collectd segfaults