Add profiling and POST size stats

Enable collector profiling by adding profile: yes in `datadog.conf`
Re-introduce raise statement that was removed by mistake
Fix per pull request comments
Ignore Vagrant
Use the same sources.list.d filename as specified in documentation

Use the same sources.list.d filename as specified in documentation for debian/ubuntu family.
Simple cosmetic logging fix
haproxy - Calculate used session percentage

Calculate the percentage of used sessions (spct) from the current number of sessions (scur) and the session limit (slim).
haproxy - Catch divide by zero
In progress
MANIFEST has jmxfetch
Only works for db-wide metrics
Tags are correct now
Per-relation and per-index metric work
Merge remote-tracking branch 'refs/remotes/origin/master' into pg-per-table-stats

Conflicts:
	checks.d/postgres.py
Update configuration
Reinstate get_library_versions
Ignore vagrant files
Don't puke on archives

raise `Skip` and continue on cleanly when coming 
across jobs that have builds which have 
been tar'd up.
Merge branch 'master' into profiler

Conflicts:
	checks/ganglia.py
Merge branch 'master' into profiler