Improve logging in kvstore's benchmark

Change-Id: I45bc52f7e660be0e53767cc12468a6bcfe8514ac
Create the raft node before starting the listener

Change-Id: Icc582c21561150941d840e8e7d3e4cdc4a0ec6c9
Add cmd args for quiet logs and random placement

Change-Id: I37745990ddae7e37eb431647db688fb6df34f881
nit

Change-Id: I066bb628e90bfb0c2c64c274fa46fa9f43377aea
s/Do/do/g in bench

Change-Id: I41bfb06226662f836ec1bf444ec6c707323dc92a
Reimplementing batching as 4 goroutines

Having one go routine to collect messages and different ones for sending
messages resulted in a high timer overhead. This commit creates four
independent goroutines each collecting and sending their own message
types. This resulted in 40% less timer overhead.

Change-Id: I658340593f387fc9624cbb73a09e7bd1df1a61ad
Recruite bees in parallel

Change-Id: I421aaa03d9c18130b525c18ae6951c395d7004e6
Export AppCellKey

Change-Id: I116e55de94f8560d66070fdbda8473f8cb891c24