Added new section "Using sound"
- some fixes and additions to the bochsrc section
- minor other changes
- TODO: remove SB16 section after updating related one in the developer doc


git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@11759 6c8e4198-a580-4521-a02f-c9ae86df1db9