Refactor TORConfiguration to be better

[conradev]

• Allow setting multiple values for the same key (i.e. multiple ControlPorts)
• Switch from ControlSocket to ControlPort
• Add a method to TORController to inflate a TORConfiguration using GETCONF
• Add popular/obvious missing flags that should be in there
• Put stuff in TORConfigurationTests.m

[chrisballinger]

Onion service configuration would be great. :)