New features:
- Attachments: Send files to the phone (#25, #15)
- Click action: Add a click action URL to notifications (#85)
- Battery optimization: Allow disabling persistent wake-lock (#76, thanks @MatMaul)
- Recognize imported user CA certificate for self-hosted servers (#87, thanks @keith24)
- Remove mentions of "instant delivery" from F-Droid to make it less confusing (no ticket)
Bug fixes:
- Subscription "muted until" was not always respected (#90)
- Fix two stack traces reported by Play console vitals (no ticket)
- Truncate FCM messages >4,000 bytes, prefer instant messages (#84)