Cluster: forced failover implemented.
Cluster: forced failover implemented.

Using CLUSTER FAILOVER FORCE it is now possible to failover a master in
a forced way, which means:

1) No check to understand if the master is up is performed.
2) No data age of the slave is checked. Evan a slave with very old data
   can manually failover a master in this way.
3) No chat with the master is attempted to reach its replication offset:
   the master can just be down.

Hailei/redis,splitice/redis,MSOpenTech/redis,ttuna/msot-redis,louisliangjun/redis,ttuna/msot-redis,ramonsnir/redis,MSOpenTech/redis,xuzhezhaozhao/redis_reading,himoca/redis,maodeyi/redis_lua,spearhead-ea/redis,himoca/redis,Hailei/redis,ttuna/msot-redis,ksarch-saas/redis,Hailei/redis,HunanTV/redis,splitice/redis,HunanTV/redis,himoca/redis,xuzhezhaozhao/redis_reading,darksideofthemoo/redis-histogram,spearhead-ea/redis,slfs007/mk-redis,MSOpenTech/redis,ramonsnir/redis,jxwr/redis,Hailei/redis,jxwr/redis,jxwr/redis,xuzhezhaozhao/redis_reading,ttuna/msot-redis,MSOpenTech/redis,louisliangjun/redis,slfs007/mk-redis,HunanTV/redis,darksideofthemoo/redis-histogram,ksarch-saas/redis,splitice/redis,ksarch-saas/redis,louisliangjun/redis,louisliangjun/redis,spearhead-ea/redis,xuzhezhaozhao/redis_reading,MSOpenTech/redis,darksideofthemoo/redis-histogram,ramonsnir/redis,slfs007/mk-redis,maodeyi/redis_lua,HunanTV/redis,darksideofthemoo/redis-histogram,splitice/redis,ttuna/msot-redis,ksarch-saas/redis,maodeyi/redis_lua