Provide sound schemes for PyRoom

The idea here is to enable PyRoom to play sounds and define sound schemes. Of course, optional, since that would disturb some of the users. What's the profit here? First, it is needed for the alarm system. Second, many users would like (although it can be disturbing) to have, for example, typemachine sounds in their editor! Which would be really nice as soon as PyRoom gets the support for "cursor-at-eye-level" thing, which actually also resembles the typewriters idea.