Merging r4193, r4194:

Merging r4193, r4194:

Autoindex fixes:

*) Autoindex: escape '?' in file names.

   For files with '?' in their names autoindex generated links with '?' not
   escaped.  This resulted in effectively truncated links as '?' indicates
   query string start.

   This is an updated version of the patch originally posted at [1].  It
   introduces generic NGX_ESCAPE_URI_COMPONENT which escapes everything but
   unreserved characters as per RFC 3986.  This approach also renders unneeded
   special colon processing (as colon is percent-encoded now), it's dropped
   accordingly.

   [1] http://nginx.org/pipermail/nginx-devel/2010-February/000112.html

*) Autoindex: escape html in file names.