* Added support for showing, creating, editing, and RSVP-ing to gatherings.
* Crash fixes and performance improvements.
* Refreshed the wiki app user interface.
* Made the app launcher the default view.  The ssb app can be set the default again by long-pressing it.
* Added a README.md to every stock app with a brief explanation.
* Fixed an issue where invalid messages were sometimes accepted.
* Update CodeMirror, libbacktrace, musl-libc, prettier, and sqlite.
