Add ability to show metadata to SVGs
Inkscape and other SVG editors let you add a ton of useful metadata to SVGs which duplicates the stuff that we currently put on the image page.
contains the licence, language, author, description, etc.
The attached patch does two things:
- adds the ability to show SVG metadata on image pages, and
- renames wgShowEXIF to wgShowImageMetadata. But I'm not sure how to auto-detect this as we did before, so it's hardcoded to 1 instead for the moment.