Shotwell 33.alpha.2:

• Forward-port of bugfixes from stable branch
• Rename Appdata -> Metainfo
• Introduce Toasts to replace simple dialogs
• Add support for opening URIs with the viewer
• Translation updates
• Fix image oversion jumping to top on first use
• Remove loads of deprecated GTK api where possible
• Remove deprecated calls to GExiv2
• Remove import from application infrastructure
• Fix missing default menu on sidebar
• Fix showing help when running from build folder
• Re-add all drag and drop based features
• "Asyncify" a lot of functions
• Clean up stray debug output left all over the code