uniform use of comments for Bochs modifications

We need to be able to grep for our manual changes.  It doesn't help to
have variations with "TUDOS" or "BOCHS-MODIFIED" around.  Please
understand "// DanceOS" comments as an abbreviation for "this code was
manually modified and needs to be manually ported once we switch to a
newer version of Bochs."

git-svn-id: https://www4.informatik.uni-erlangen.de/i4svn/danceos/trunk/devel/fail@1747 8c4709b5-6ec9-48aa-a5cd-a96041d1645a