add @strider commit message hints

Parse the hint below and set environment variable `$STRIDER_HINT` to "test this".
@paperg-ci test this

Added unit tests for the new hints module.
Also fixed semicolons in job.js and removed some unused code.
@ktlicu sure, good point. My goal this time around was to put in semicolons everywhere they ought to be put. Whoever wrote this apparently really hated semicolons.