Added plugin for procenv (process environment).

Signed-off-by: James Hunt <james.hunt@ubuntu.com>
Added plugin for Upstart (event-based init daemon).

Signed-off-by: James Hunt <james.hunt@ubuntu.com>
Merge pull request #206 from jamesodhunt/master

Addition of plugins for procenv and upstart.
Signed-off-by: Adam Stokes <adam.stokes@ubuntu.com>