* net: Split resolving out of CNetAddr
* net: Split resolving out of CService
* net: Split resolving out of CSubNet
* net: move CNetAddr/CService/CSubNet out of netbase
* net: narrow include scope after moving to netaddress
Net functionality is no longer needed for CAddress/CAddrman/etc. now that
CNetAddr/CService/CSubNet are dumb storage classes.
* net: Add direct tests for new CSubNet constructors
* net: Have LookupNumeric return a CService directly
Also fix up a few small issues:
- Lookup with "badip:port" now sets the port to 0
- Don't allow assert to have side-effects
* net: fixup nits
