* Only store and connect to NODE_NETWORK nodes
* Keep addrman's nService bits consistent with outbound observations
* Verify that outbound connections have expected services
* Don't require services in -addnode
* Introduce enum ServiceFlags for service flags
* Introduce REQUIRED_SERVICES constant
* CAddrDB modified so that when de-serialization code throws an exception Addrman is reset to a clean state
* CAddrDB modified to make unit tests possible
* Regression test created to ensure bug is fixed
* StartNode modifed to clear adrman if CAddrDB::Read returns an error code.