FreeDesktop Completeness - Mimetypes

[snwh]

Complete all these icons at all sizes for fd.o completeness

• [x] application-x-executable
• [x] audio-x-generic
• [x] font-x-generic
• [x] image-x-generic
• [x] package-x-generic
• [x] text-html
• [x] text-x-generic
• [x] text-x-generic-template
• [x] text-x-script
• [x] video-x-generic
• [x] x-office-address-book
• [x] x-office-calendar
• [x] x-office-document
• [ ] x-office-presentation
• [x] x-office-spreadsheet