Clean up AmpacheApi module

Remove trailing whitespace.
Centralise debugging by using a function.
Add an optional debug callback for passing debug messages up the chain.
Try to be more robust in Dba
Make remote catalogs actually work
Try to fix remote streaming
Don't store plaintext passwords

http://dbareactions.tumblr.com/post/41455377237/when-i-see-app-passwords-stored-in-clear-text-in
Fix Rating::gc()
Fix User::count()