WIP: upgrade pt-agent.
First working pt-agent upgrade.
Merge branch 'master' into upgrade-pt-agent
Set config dir 700 and config/* 600 (PCT-521).
Add revision to percona-agent -version.
Don't throw error if mysql.DSN.Socket and .Hostname are set.  Build pkg in versioned dir.
Fix parsing my.cnf.
Merge pull request #36 from percona/upgrade-pt-agent

Upgrade and remove pt-agent during install