Fixes after first round of reviews
    
    Drop the paragraph starting with "RPM packages must not require
    or recommend packages containing a .desktop file" — this only
    makes sense in limited cases, and the general packaging rules
    which are already referenced in this document are enough.
    
    Drop most of the guidelines and rules about Duplicated and
    Replacements and simply say that FESCo must decide in case of
    conflicts or replacements.