hddtemp fixes.
    
    Clean up network control section.
    Implement hddtemp_etc_t for /etc/sysconfig/hddtemp. The advantages are:
    - hddtemp_t no longer needs access to read all generic etc_t files.
    - allows us to implement a meaningful hddtemp_admin()
    
    Signed-off-by: Dominick Grift <domg472@gmail.com>
    Signed-off-by: Chris PeBenito <cpebenito@tresys.com>