* OpenPGP: Improved support for encrypting with subkeys
* OpenPGP message status icons were not visible in message header pane
* OpenPGP Key Manager was missing from Tools menu on macOS
* Creating a new calendar event did not require an event title
- remove python2 dependencies for TW
- support wayland mode/autodetection in startup wrapper
- replace some Requires to use requires_ge macro where appropriate
- improve langpack build (as already used for Firefox)
- add ccache statistics output to build
OBS-URL: https://build.opensuse.org/package/show/mozilla:Factory/MozillaThunderbird?expand=0&rev=555