Fixes #888.

Remind the user to sign in

See merge request briar/briar!841

Use message icon rather than mail icon for private messages

Closes #1032

See merge request briar/briar!846

Add feature flag for dark theme

See merge request briar/briar!843

Display log file in a reader-friendly way

Closes #1307

See merge request briar/briar!845

Dark Theme Fixes

See merge request briar/briar!844

Factor out keyagreement ui theme

See merge request briar/briar!835

Upgrade Android Gradle Plugin to 3.1.3

See merge request briar/briar!842

Implement Dark Theme (DayNight with automatic option)

See merge request akwizgran/briar!818

This is just a first rough implementation.
A real UI designer should look over this.

Language improvements

See merge request akwizgran/briar!829

Resolve ""Decrypting database" label needs some padding"

Closes #1297

See merge request akwizgran/briar!830

Use project path for translation verification

See merge request akwizgran/briar!840

Add utility method for logging exceptions

See merge request akwizgran/briar!838

Don't hide UI on low memory if we're in the foreground

See merge request akwizgran/briar!839

Replace logging boilerplate with a static method

See merge request akwizgran/briar!837

Move logging of time measurements to FINE level

See merge request akwizgran/briar!836

Don't show Huawei protected apps button on API 24+

Closes #1291

See merge request akwizgran/briar!823