Start background jobs when starting a project.
Stop background jobs when stopping
Fix check for empty location

I had switched the two conditions, empty and not empty. This fixes that so we
don't try to clone when it exists.
Update error message for missing directory

We want the error message to be a bit more informative. This tells us what the
expected directory is.
Add basic config script.

This is a simple lua script to handle getting and setting config values. It
cannot deal with sections like an ini file right now. Probably fine to use a
basic format however.
Use config script to delete location

The config script can delete the locations, no need to do it ourselves with
grep.
Don't load _MGR_DEV on startup

We will use the config script to access that value as needed. We should not
always load it up as most scripts don't need it anyway.
Use config script

Now we load values from the config script whenever we need them, instead of
grepping and cutting and the like. Also we rely on the config script for
deleting values.