adds icons for five work types
Displays Audio & Video players ref #31 #32 #46, displays correct icons & thumbnails in search results ref #44 #22
Adds almost all DC metadata fields for Collections ref #24; Collections do not require license field.
adds dc:date to Image edit form ref #12
[worthwhile] UNFINISHED beginning work on switch to worthwhile
[worthwhile] UNFINISHED continuing work on switch to worthwhile