* Undid previous commits of doing fancy exception handling. Decided should expose errors to user, so they can do something about it.
* Added exceptions to ITorrentClient, hence interface dealers what exceptions it throws.
* Undid support for single file torrents, need a better plan for managing this.
BugFix: Switch to using ITorrentDetails instead of TorrentDetails for added torrent response type. This results in a null. Return type must be concrete.