ReactOS should provide at least some legacy audio driver

As the title explains, there are no legacy audio drivers included in ReactOS.
In the source tree, there are some bits for a legacy Sound Blaster driver, with some pieces of code that probably come from a linux driver, but actually it is not working and it is not even compiled. Perhaps it would be better to delete it and move it to rosapps branch if it is useless; however I think that one day it should exist something working on this purpose.