Merge changes I699bab32,I731f5709,Ieacfdb3b,Id29cfe56,Ie242b7af

* changes:
  [WifiScoreCard] Reads after MemoryStore install
  [WifiScoreCard] Add doWrites
  [WifiScoreCard] Handle merging of stats
  [WifiScoreCard] A read/write MemoryStore interface
  [WifiScoreCard] IpMemoryStore plumbing