Added the new Grafana dashboard  to tools.rst
added graphite-module to pythonpath

Running build-index failed importing python module. It is not in python path by default, so I would propose to add default path before execution.
Merge pull request #599 from ImmobilienScout24/rebase_442

added graphite-module to pythonpath
add missing colon
Merge pull request #600 from ImmobilienScout24/rebase_442

add missing colon
Merge pull request #595 from torkelo/master

Added the new Grafana dashboard  to tools.rst
Open a socket and compare source IP with destination in is_local_interface
This change fixes an issue where if /proc/sys/net/ipv4/ip_nonlocal_bind  is set to 1, remote
addresses where detected as local.
fixed whitespaces
added test for is_local_interface function