Version 3.5
Directory list can now be sorted by column: name, size, timestamp, or ext.
3.24.23 & 3.4.24 DO NOT WORK IN IE!
     I don't know why yet, mostly likely js related.
New: $_['ext']            = 'ext';  // filename.ext(ension)
New: $_['folders_first']  = 'folders first';
New text "icons": $ICONS['dir'] = '[+]'; $ICONS['folder'] = '[+]';
Index_Page(): get dir list, don't sort server side, but filter . & ..
Create_Table_for_Listing(): Added <a>'s & onclicks for sort calls
Create_Table_for_Listing(): Also switched from all echo "...", to direct html
  (except for a few echo's...)
Get_DIRECTORY_DATA(): improved determination of $ext.
Get_DIRECTORY_DATA(): added DIRECTORY_DATA[x][5] = $ext (for client side sort)
Index_Page_scripts(): added a few global js variables for client side sorting.
            New ()'s: Sort_Folders_First(), sort_DIRECTORY()
Display_Directory_Summary(): insert via innerHTML instead of document.write.
Added some css for the directory header & footer rows.