updated SSL definition

changed the way we detect SSL usage and force SSL definition in the influxdb driver.
You now need to have influxdb version > 0.1.6
Merge pull request #627 from prune998/patch-2

updated SSL definition
fix typo in example config
Merge pull request #628 from keen99/patch-1

fix typo in example config
add btrfs to supported fs type

Now the collector can hanfle 0 inodes values without doing a division by zero, btrfs can be added to the supported filesystems to check.
Merge pull request #632 from prune998/patch-1

add btrfs to supported fs type
Merge branch 'master' of github.com:python-diamond/Diamond