* 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
Adds several unittests for CAddrMan and CAddrInfo.
Increases the accuracy of addrman tests.
Removes non-determinism in tests by overriding the random number generator.
Extracts testing code from addrman class to test class.
