Under the current system there's no distinction made on the slave side
between instance config files that are present in the filesystem and
instances actually assigned to the slave. Which could lead to problems
with determing if an instance is actually assigned to the slave.
Resolve this issue by separating discovered instances with assigned
instances. Upon startup discovered instances are put into the
discoveredInstanceInfos mapping on the Slave object and all of these are
sent to the master server. The master server in turn sends assignment
requests for all the instances which are assigned to the slave. These
are put into the instanceInfos mapping of the Slave object which can
then be relied up to include only assigned instances.
Use lib* prefix for the modules impored from the lib package to help
distinguish them more from ordinary variables. Fix up the naming
convention for files to be consistently lowercase_underscore for
JavaScript files.
Split up codebase into the packages @clsterio/lib, @clusterio/master,
@clusterio/slave, and @clusterio/ctl using lerna to manage them. This
will allow deployment to use only the parts needed reducing install
size, and better separate the code into shared library, master, slave
and control.