Configuration management functions for local builds

Event handlers for displaying build progress on an xterm, which allows
for more functionality than a dumb terminal.  The event handlers are
responsible to add information to the state, which is then used by the
renderer to periodically write that information to screen.

Event routes for local build runners.  When running a build locally via cli,
these routes will be registered in mailman and will perform all necessary
build steps.

Running a local build uses the same event flow as server-side builds.
Depending on the configuration, routes may differ (e.g. different handlers
or interceptors).  A local build can either run in a child process, or it
can run in a container.  In any case, the container jobs are run in containers
and action jobs are run by the script process.

Blobs (artifacts, caches) are always stored locally, but this can vary
depending on configuration.  If run in a container, a volume can be used.

The build controller, responsible for managing build params and events, is
run in the main process.  Builds connect to it using http, same as for 
server-side builds.

Event handlers to print build progress a terminal

Set up runtime for local builds.  These are builds where the api server is run
in the same process, and the build scripts as child processes (either native or
as containers).