Allowing custom app names

Here in Brazil the Rdio app has been renamed to "Oi Rdio" and this used to break redis-cli since the app name is hardcoded.

This pull request changes rdio-cli behavior by enumerating running applications and selecting the one matching the /Rdio/ regexp with a fallback to "Rdio".

I'm sorry by the size of the test files diff, please don't be scared by it. I had to add one level of indentation to avoid repeating code in each expectation.