Merge pull request #8 from dwagon/master

Fixes the prefix / system_name
fixed 2 tests expecting the hostname in the results
updated version information to 0.3.0
Adds docs how to use system_name argument of init
Merge pull request #9 from svetlyak40wt/patch-1

Adds docs how to use system_name argument of init
make sure the clean_metric_name() is called
More that just an API ref.
fixed up titles for API ref
Fixed up tut.
Get FQDN explicitly