Agent will run mtr traceroute on unable to connect

Additional debugging info to help with recurrences of
http://status.serverdensity.com/incidents/khr92zjq35h9
Strip out protocol as some versions of mtr don't work with it
Merge branch 'traceroute'
Add exception handling if no process list

https://serverdensity.zendesk.com/agent/#/tickets/1617
Set rabbitMQHeaders specifically

Prevents authentication details from leaking if they’re set for the
RabbitMQ check. Reported by Jesse Young <youngj@telerivet.com> in
https://serverdensity.zendesk.com/agent/#/tickets/2527
add initial test code for google disk meta data
fix layout of meta
Update checks.py

ensure meta isn't added unless populated
just return device and not each partition as well
Merge branch 'disk-meta-data' of github.com:serverdensity/sd-agent into disk-meta-data
cope with possible missing glob
Merge pull request #70 from serverdensity/disk-meta-data

Disk meta data
Updated agent's version string
Merge pull request #71 from serverdensity/release-1.13.3.1

Updated agent's version string
Initialize secondsBehindMaster to prevent crash

The if mysql_norepl is used, this variable won't be set.
Merge pull request #72 from ByteInternet/crash-on-mysql_norepl

Initialize secondsBehindMaster to prevent crash
Merge branch 'master' into master-no-url-checks