Adding OME 5 to docs dropdown menu
Update version history page to 4.4.8
Putting new menu under docs rather than products!
Leica: fix typo in primitive type creation
Changing downloads links & removing unused extlink
Check for null before passing primitive values to MetadataStore
merge develop -D org -I include -E exclude: PR 475 (Fake screens)
merge develop -D org -I include -E exclude: PR 528 (Tile performance improvements for VMS and NDPI)
merge develop -D org -I include -E exclude: PR 529 (Still more bug fixes)
merge develop -D org -I include -E exclude: PR 534 (Revert "MetadataTools: Remove deprecated and unused methods")
merge develop -D org -I include -E exclude: PR 537 (Consolidate OME-XML primitive type logging)
merge develop -D org -I include -E exclude: PR 538 (Update menu for OME 5 to docs pages & update version history)
merge develop -D org -I include -E exclude: PR 539 (Changing downloads links & removing unused extlink)