Rename tests.utils to tests.subtitle
Raise severity of "file already exists" errors
logging: print log level name first on line when verbose
Log what protocol/bitrate we selected
Get rid of some indentation by inverting conditionals
Get rid of some unnecessary thumbnail related output

Also, this change also makes svtplay-dl print an error if thumbnail was
requested but we write to stdout (--output -).
Merge pull request #144 from olof/topic/minor_tweaks

Some minor logging related tweaks