Signal Desktop: v1.5.0 Release

Note: Includes fixes from 1.4.0-beta.1 (never released to production), 1.5.0-beta.1, and one additional pull request (#2072)

Update electron to 1.7.12 (#2029)

New design for import and install flows (#2053)

Support for 'light' imports, which bring just messages, contacts and groups (#2053, #2072)

Set conversation disappearing messages state and contact block state on initial link (#1980)

'Restart' -> 'Restart Signal' button in update dialog, thanks @StevenXL (#2024)

Fixed: If app started offline, conversations would not open (#2064)

Fixed: Attached images would sometimes show up rotated improperly (#2040)

Fixed: Uncaught Exception: TypeError; 'getSize' (#2061)

Fixed: File paths with special characters could be shown in misleading way

Fixed: incoming messages sometimes didn't appear at all (#2050)

Fixed: 'Cannot find module ./app/locale' error popup when attempting to start another instance of the app on Windows (#2017)

Fixed: Setting NODE_ENV environment variable to 'development' would point it at staging servers (#2010)

Dev: - Move ESLint environment configuration into .eslintrc (#2051) - Sync Protocol Buffers with libsignal-service-java (#2046) - Update to libsignal-protocol-javascript v1.3.0 (#2050) - Make our binary comparisons constant time (#2047) - Fix typo in issue template (#2020) - Update to new signal branding (#2018)