some more logging around connecting to carbon
log the number of files processed at INFO show the log shows activity.
Some logging fixups to make debugging a bit easier and more useful.
consistently use replacement_character
add unit tests, escape `.` found within the labels of perfdata

Uses the pytest testing library.
escape more weird characters in perf data labels

For one of my windows servers `check_snmp_storage` is returning crazy
stuff like:
    'D:\_Label:Data__Serial_Number_8c4da61a'=209524MB;2310;4620;0;230998

This patchs add `:\` to the list of characters we replace when in
`process_nagios_perf_data`
Merge pull request #16 from AccelerationNet/bugfixes

Bugfixes