RFB code cleanup and small additions
- quit simulation if the client has disconnected
- moved update region checks to new function rfbAddUpdateRegion
- changed the order of methods and function in the file


git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@11703 6c8e4198-a580-4521-a02f-c9ae86df1db9