photon v0.10.0

Unsigned installers. See the README for the security warnings each OS shows, and how to get past them.

What's Changed

• perf: walk the thumbnail cache at startup only when it can hold garbage by @bsg62 in #28
• feat(viewer): Picasa-style caption, click-to-copy, and a context menu by @bsg62 in #29

Full Changelog: v0.9.1...v0.10.0