Ticket 284 - Remove unnecessary SNMP MIB files
    
    We currently carry around some standard MIB files in our soruce tree
    and install them as well.  Aside from our DS specific MIB file, these
    are all included as a part of the Net-SNMP distribution.  We should
    not be carrying these files around as well.
    
    This patch removes the standard MIB files from our tree and updates
    the Makefile to avoid installing them.
    (cherry picked from commit ee320163c6b7913ddae41cb8954b237d1b99eadf)