Classify some of the input filters as the correct types. Previous to

Classify some of the input filters as the correct types.  Previous to
this patch, the type wasn't too important, because all filters were
put on the same list.  After this patch, the filter type is very important,
because there are three different types of filters, and they are all treated
differently, namely:

CONNECTION:	Filters of this type are valid for the lifetime of this
		connection.
PROTOCOL:	Filters of this type are valid for the lifetime of this
		request from the point of view of the client, this means
		that the request is valid from the time that the request
		is sent until the time that the response is received.
CONTENT:	Filters of this type are valid for the time that this
		content is used to satisfy a request.  For simple requests,
		this is identical to PROTOCOL, but internal redirects
		and sub-requests can change the content without ending
		the request.

It is important to realize that the three major types above are actually
broken down into smaller groups in the code, to ensure that the ordering
of filters is always correct.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@93688 13f79535-47bb-0310-9956-ffa450edef68