Another update

1. 991a0cc model: Generalizing content store implementation by Alexander Afanasyev · 12 years ago
2. 1a2df6a Small reorganization of utils/ folder contents by Alexander Afanasyev · 12 years ago[Renamed from utils/persistent-policy.h]
3. 2b4c947 Another set of refactoring by Alexander Afanasyev · 12 years ago
4. e77db79 Normalizing namespace usage (ndnSIM namespace is now always under ns3) by Alexander Afanasyev · 12 years ago
5. 30f60e3 Some progress on CcnxPit. Partially working by Alexander Afanasyev · 12 years ago