Lint police

Fix lint errors.
Add jslint pre-commit hook.
I'm cool with having a `hooks` specific name for a task that gets called from hooks, but I would prefer we make one change:

`scripts:lint` should look at an environment variables to decide whether the process should `exit(1)` if lint errors are found.  This will let us easily integrate "fail on lint error" in the build process, while still letting in-development work have lint errors.