Fail when Nova API, Nova network and Swift hosts are not set as IP addresses

- Refactor value validator system - cleanup, pep8, documentation, tests and allow multiple validators for each parameter

Change-Id: I69ac806d9efdb46196070d518d5ef5c5c174e6bb
Fixes: rhbz#886603
Added RHN Satellite registration possibility.

Change-Id: I74f2560f12d1a36d3b07029ab0fc345ba009af55
Fixes: rhbz#905368
Raise NetworkError when ScriptRunner fails to connect.

Change-Id: Iff96809f44ce0dcd92b28dbebadffa4000a5b4b3
Fixes: rhbz#908838
Merge "Added RHN Satellite registration possibility." into folsom
Merge "Fail when Nova API, Nova network and Swift hosts are not set as IP addresses" into folsom