Changes to the virt policy module
    
    Fix inconsistency between virt_cache_t and svirt_cache_t
    Libvirtd reads virt log files
    Take away virt_domains capability to use nsswitch and allow them to read
    etc_t file instead for /etc/passwd
    svirt manages svirt_image_t symlinks and sock files
    
    Signed-off-by: Dominick Grift <dominick.grift@gmail.com>