*Title: tipafriend_top_list extended fetch function

*Documentation:
New field 'requested' which contain time-stamp of added table entry was added to
eztipafriend_counter table. This gives possibility to fetch top list of requested
nodes for a certain time duration.
Accordingly, content/tipafriend_top_list fetch function was extened with new parameters.

*Usage:

fetch( 'content', 'tipafriend_top_list',
       hash( [ 'offset', offset, ]
             [ 'limit', limit, ]
             [ 'start_time', start_time, ]
             [ 'end_time', end_time, ]
             [ 'duration', duration, ]
             [ 'ascending', ascending, ]
             [ 'extended', extended, ]
              ) )
*Parameters:
Name:          Type:        Required:
 offset         integer      no
 limit          integer      no
 start_time     integer      no
 end_time       integer      no
 duration       integer      no
 ascending      boolean      no
 extended       boolean      no


*Example:

{def $tip_top_list=fetch( 'content',
                          'tipafriend_top_list',
                          hash( 'offset', 2,
                                'limit', 4,
                                'start_time', maketime( 0, 0, 0 ),
                                'duration', mul( 60, 60, 24 ),
                                'ascending', 0,
                                'extended', true() ) ) }
{ $tip_top_list | attribute( show, 1 ) }
{undef}