Handle machines that never sent any data to graphite

* Add enabled_time and activated fields in machine model.
* While a machine is not activated, mist.alert checks if it has
  sent graphite any data and ignores any rules. Once the machine
  sends graphite some data, mist.alert changes its state to
  activated and starts checking the rules.
* Add method in GraphiteSeries base class to check available
  metrics in graphite for given uuid.
Improve logging in alert
Add view to produce graphs with bucky and collectd's data
Fix aliases and add diff cross graphs
Fix params in graphite call for cross stats
Merge pull request #6 from mistio/mand

Mand
Add config options to switch graphs/alert to bucky

False by default
Merge branch 'master' into bucky
Merge branch 'bucky.cross_graphs' into bucky
Make supervisord autorestart bucky, change branch
Start supervisord as root, run most as mist

only collectd runs as root
Add time in bucky's log
sumSeries in NetSeries (wildcard ifaces)
Add src/bucky/ to .gitignore