Exceptions

[jagrosh]

Right now, when lyrics cannot be successfully retrieved, the client returns null. This happens almost regardless of what went wrong, whether it be an internet connectivity issue, a site issue, a parsing issue, etc. While this was originally set up this way to make using the library easy, some users might want to be able to debug why their lyrics searches are failing. Therefore, I think the client should provide a method to retrieve lyrics that doesn't mask the exceptions behind a 'null' and instead returns meaningful information as to why a search failed.