Fix rafter:start_cluster

Currently rafter_log creates a rafter_hint ets table. When multiple rafter_logs
are started on one machine this can lead to an ets error. Make the hints table name
specific to the peer.
Simplify generation of HintsTable

Fixed in response to code review comment
Merge pull request #27 from apanda/master

Fix rafter:start_cluster
use rafter_voting:member
Merge branch 'feature/structured-voting'
Merge branch 'master' into benchmark
merge master