Adding postgresql replication lag monitoring
Adding DNS resolution check.
Cant access settings unless inside the handle def

Movings the settings accessors to inside the handle block as they will fail if they are outside.
Merge pull request #68 from zsiddique/master

Fixing the mailer handler
[cpu-usage] cpu usage metric plugin (bash), produces %
[haproxy] updated the haproxy check, sonian deploys this one
Merge pull request #69 from portertech/cpu-usage

[cpu-usage] cpu usage metric plugin (bash), produces %
Merge pull request #70 from portertech/haproxy

[haproxy] updated the haproxy check, sonian deploys this one
Merge pull request #67 from nstielau/dns_plugin

Adding DNS resolution check.
[graphite] added extension to check-data (.rb)
[graphite] check-data.rb +x
[graphite] seen a last value of nil, need last recorded value
[graphite] the guys at heavywater already had a better solution
improvements for memcache:
- make the graphite plugin work
- use default
- reformat

I also added a Gemfile so development is easier
Merge pull request #73 from kwarter/memcached

improvements for memcache:
Cleaning up check-specific dependencies.

This commit removes some check-specific dependency files,
adds a note to the read-me about how to specify
dependencies, and adds such a specifiction to the header
of the memcached-graphite.rb plugin.
Merge pull request #74 from nstielau/master

Cleaning up per-check dependencies
Merge pull request #75 from tarhelypark/master

event changed from local to instance variable
Temperature metrics using lm-sensors in linux
Fixing temperature-metrics to work with sensors