DocumentInfo can add additional information to HTML documents.  One
use for this filter is to include the Last-Modification date is in the
header or footer of HTML documents.  Any HTTP header information can
be displayed as well as some builtin attributes.  The resulting
information can be displayed at the top or botton of the document and
can be aligned to either the left or right side of the page.

Information to be displayed is specified using a key.  For HTTP
headers, the key is the HTTP header name.  Other builtin keys
are:

    URL - URL of the HTML document
    Client -  client IP address and hostname
    Date - current date
    LastModified - Last modifcation date in localtime

Some useful HTTP headers to include are:

    Server - server software version
    Content-length - number of bytes in document
    Referer - referring document

This filter has the following configurable preferences:

* DocumentInfo.info

  Comma separated list of information to display.
  Example: "URL,Server,Client,LastModified,Date"

* DocumentInfo.location

  Place the information at the "top" or "bottom" of the page.

* DocumentInfo.align

  Align information on "left" or "right" side of the page.

* DocumentInfo.htmlAfter

  HTML to insert before the inforation

* DocumentInfo.htmlBefore

  HTML to insert before the inforation


