Changes to file icons and search result loading.

Changed code to handle .pdf and .png files (.png has wrong image that
states .jpg). Changed logic of loading search results. New solution is
to force load all the entities that still have no author information,
this means that those entities did not previously exist within the
system and thus their full information has not yet been loaded from the
server (possibly a better solution exists, maybe adding a marker to the
entity that it has been loaded, setting that from within SSEntityDescGet
call along with the results).