Visual changes: - New colors and message bubbles - Unified theme - Video playback updates - Disappearing messages can now be enabled without first turning them on with a '1 day' duration - The status of the last conversation message (if outgoing) is now shown in the left pane - One-click access for replying to message

Media Gallery: - Fixed: Wrong attachment would be saved from lightbox after left/right navigation - Better handling of videos - thumbnail of video is now used - Dark theme honored in all UI elements - Icons shown for all if no thumbnail is available

Begin SQLCipher migration. First stage: all messages and temporary message cache.

Fixed: When returning from idle, a conversation would sometimes be missing a set of messages

Fixed: When marking safety number as verified/not verified, that state would not sync to mobile device

Fixed: Deleting conversations with a large history would sometimes fail

Fixed: Sometimes triple-dot menu for replying to message would show up off-screen

Fixed: In some cases, messages would show up out of order. This should now be far less common.

Update localization strings

Dev: - New version 8 schema for messages: thumbnails and dimensions from image and video attachments, as well as a full-size video screenshot for use in conversation view - Much of the application has been moved to React - Dark theme rewritten from scratch - New CSS is now using Block Element Modifier syntax (BEM) for info: http://getbem.com/ - JSHint removed from project; ESLint now scans entire project - _locales/en/messages.json is now included in jsprettier runs - All backbone-related functionality removed from Style Guide - Ensure set of Linux dev dependencies is complete in Contributing.md - Introduce mandatory migration on startup, to minimum version 7 - Preserve migration state when deleting config due to failed login - Conversation: store lastMessage/lastMessageStatus in memory only - Moved to using window.log only for all browser-context logging, with new eslint rule to prevent direct use of console.log - Full eslintification of files in libtextsecure to take advantage of new console.log rule - Removed unnecessary and too-verbose console logging - When making thumbnail for video attachment to be sent, we generate a 100x100 preview instead of taking a full screenshot of the video