ACCUMULO-2579 Create a table explicitly for storing replication bookeeping.

Lift some stuff out of MetadataSchema to make a ReplicationSchema. Remove replication specific things from
the Metadata table util classes (where applicable) and update invocations.
ACCUMULO-2579 Create a replication up-front at initialize in the system namespace
ACCUMULO-378 Remove replication entries from metadata table

There's no need to create these records as it doesn't actually save any work in the end.
We would still have to read just as much as compared to not having them.
ACCUMULO-2579 Get a bit farther where we can read the root table
ACCUMULO-378 move back to making the replication table a "regular" table.

I couldn't get the magic incatation to make a table at accumulo-init time
to actually work. No matter what I tried, it would never be read from disk
despite the data actually being there. Scratch the idea, and move towards
a normal table and using provided credentials.