another massive rework

I sincerely apologize for mixing refactoring and feature changes,
regressing the project and complicating code review.

Things that have changed:

 *  Communicator have been renamed to Sparkle and is now using the
    standard Racket's logging infrastructure.

 *  The storage and networking managers have been disabled until
    they are ported to dds (dynamic dependency solver).

 *  New dds-compatible components have been added to cover all
    previous functionality.

Signed-off-by: Jan Dvořák <mordae@anilinux.org>
fix bond component contracts

Signed-off-by: Jan Dvořák <mordae@anilinux.org>
added reference-counting dependency solver

Our rc-solver wraps the solver from dds package and adds de-duplication
and reference counting, allowing our managers to define identical
targets multiple times.

Signed-off-by: Jan Dvořák <mordae@anilinux.org>