3.0.0

• Converted to a WebExtension for Thunderbird 78 compatibility, as Thunderbird has dropped support for legacy bootstrap extensions. Thanks @homo-programmatis for navigating some of the underlying API changes. (Fixes #26)
• Change to use WebExtension local storage APIs instead of the legacy preferences system.
• New "modern" icon style to match with current Windows design conventions. (Fixes #24)

v2.0.0

Conversion into a WebExtension to support Thunderbird 68. Because of this, this version of the extension is not supported in pre-68 Thunderbird versions; please use 1.x versions for that. (Thanks @jamesg-nz)

Support for a user preference to count only the primary inbox. (Thanks again to @jamesg-nz)