Some more work on the SB16 and lowlevel sound documentation
- removed SB16 section in the user doc and partly update the developer doc
- some additions in the section "Using sound"
- TODO: update the sound output classes stuff in the developer doc


git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@11760 6c8e4198-a580-4521-a02f-c9ae86df1db9