A legacy mkdir function was still being used by the
generate_system_fsentries function. However, it wasn't necessary because
we now associate fsentries by uuid, eliminating the requirement to
create the home directory separately from its subdirectories.
The old mkdir function was removed, and generate_system_fsentries was
moved to a new service called UserService, which is intended to
eventually hold all methods related creating, removing, and updating
users.
The kdmod module was broken since we renamed packages/ to src/. Also,
the update to mod loading for some unknown reason now requires each call
to require to end with `.js`. As far as I know, this was working
previously.
Allows modules to register a listener to the 'install' event without
creating a Module class. This changes how external modules are
installed.
External modules are now referred to as "extensions"; this commit does
not update the term but does use 'extension' as the name of the global.
