Behavioral flags for memory work better

Flags such as writeToMemory, dbCacheSize, etc. should be working now.
Remember to set these variables in each package when doing tests.

The exception is memoryLimit, which isn't really implemented yet.
Merge branch 'master' of https://github.com/pranjalv123/mexos

Conflicts:
	src/paxos/paxos.go
	src/shardmaster/server.go