* [NOD-557] Remove regTest network.
* [NOD-557] Remove remaining references to regTest.
* [NOD-557] Move newHashFromStr from params.go to params_test.go.
* [NOD-557] Rename test to network in register_test.go.
* [NOD-557] Replaced removed tests in TestDecodeAddressErrorConditions.
* [NOD-1223] Move all network stuff into a new network package.
* [NOD-1223] Delete the unused package testutil.
* [NOD-1223] Move infrastructure stuff into a new instrastructure package.
* [NOD-1223] Move domain stuff into a new domain package.