Refix the entity tag comparisons for If-Range, If-Match and If-None-Match.

Comparisons need to be case sensitive and in all but one case (cache update)
need to be strong comparisons, taking into account the possibility that
any of the current Etag or the one(s) received from the client may be weak.

Changed name of ap_find_list_item() to ap_size_list_item() to be consistent
with other find routines and added new (simple) ap_find_list_item(), whose
implementation will eventually be replaced with something more efficient.

PR: 2065, 3657
Submitted by:	Roy Fielding, Ken Coar, Dean Gaudet


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@82779 13f79535-47bb-0310-9956-ffa450edef68