Added chain configuration options and write out during genesis database
insertion. If no "config" was found, nothing is written to the database.
Configurations are written on a per genesis base. This means
that any chain (which is identified by it's genesis hash) can have their
own chain settings.
NOTE: For known, non-consensus, hard to reproduce bugs consider the
following method `common.Report("extra", stuff, "you need logged")` will
give you a stack trace and a friendly request to submit it as an issue
on our issue tracker.
