[rack_env] set rack_env to production, for optimizations
[upstart] updated sensu-client upstart script for 0.9.12
[upstart] use PROG to make it easier to cp/modify
[upstart] updated remaining upstart configs
[systemd] updated systemd sensu service scripts for 0.9.12
Merge pull request #43 from portertech/rack_env

[rack_env] set rack_env to production, for optimizations
Merge pull request #44 from portertech/upstart

Updated upstart sensu service scripts for 0.9.12
Merge pull request #45 from portertech/systemd

Updated systemd sensu service scripts for 0.9.12