Copy English audio cues for Spanish translation

Copy the English audio cue translation into a new `res/values-es/`
directory, ready for translation.
Add Spanish translation for audio cues
Remove extraneous whitespace
Add Spanish audio cues to changelog
Improve Spanish translation of 'paused'
Improve Spanish translation of 'resumed'
Merge pull request #59 from mattbostock/spanish-audio-cues

Add Spanish translation for audio cues