Remove capabilities instead of setting empty caps via. --setcaps
    
    If a file in a package does not have any capabilities rpm --setcaps should
    remove capabilities of the file. Prior to this patch capabilities of the file
    were set as empty.
    
    Empty capabilities mean more than no capabilities. A file with no capabilities
    can inherit capabilities, but file with empty capabilities can not.
    
    When ever package does not have any capabilities set %|FILECAPS? is false.
    If some files have capabilities, %|FILECAPS? is true but %{FILECAPS} is ''
    when the file does not have capabilities and '= <capstring>' when there is some.
    
    Reported and patch created by Markus Linnala
    Commit message edited by Pavlina Moravcova Varekova and Florian Festi.
    
    Fixes #585
    Fixes #586