Install snapshot and Reply

1. InstallSnaphot change in Leader
2. Moved Snapshot out of RaftActor
3. Follower ApplySnapshot changes
4. InstallSnapshotReply changes in Leader
5. Installing Snapshot made in chunks
6. Implemented ProtocolBuffer for InstallSnapshots
7. Sanpshots as ByteStrings
8. Create snapshots made aysnc using CaptureSnapshot messages
9. Save Snapshot Failure Rollback
10. LeaderTest for send snapshot and snaphot reply

Change-Id: I16acc20ac7f671e89c5fbdb7aebd6dbe72e5f6e0
Signed-off-by: Kamal Rameshan <kramesha@cisco.com>