Various fixes and cleanups
Comments on raft data structures
Ignore revo from prior terms
AppendEntries mostly working
64-bit entry numbers in some calls
Use motes instead of u2_raty
u2_sist structure
Various minor fixes

Also remove the checkpoint notification for now.
Start u2_reck entry numbers from 0
Remove did
Options cleanup

Remove sow and rez, add comments with flags and short descriptions. Also
correctly bound ports.