multi-letter state symbols for info/content

In http://localhost/info/content?<URL>

  'X' if the URL is in the DontGet section of the configuration file,
  '+' if the URL is in the cache, '~' if it has been requested and '-'
  if it is not cached.

Actually there should be several state indicators:
[DC] in DontGet, but already in the cache, [dC] not in DontGet, but
already in the cache. Wait, there are also images=no images, so a
third field, "not to be fetched", is called for, etc.

As many fields as necessary to nail down (fully describe) the status
of the URL. As this isn't a page we look at all day, it's OK to fill
it up with more fields.

Otherwise users will be baffled as to why images show up as "+", even
though one has images=no (today, but not last week!)

P.S., just like "ls -l" "drwxr-xr-x" the future fields should line up
nicely, no matter what their toggle/state.