Release 3.22.1

Overview of changes in Sysprof 3.22.1

Changes since 3.22.0

 * A new data source called "hostinfo" has been added. It records various
   CPU datapoints as "counters" in the sysprof capture.
 * A new visualizers abstraction has been added so that we can start
   providing new ways to look at profiler data.
 * A CPU visualizer has been added which renders datapoints recorded
   from the hostinfo data source.
 * Selecting ranges of the visualizer will update the callgraph limiting
   stacktrace samples, to the given time range.
 * Missing headers are now installed which may be needed by applications
   using libsysprof-ui.
 * A keyboard shortcuts dialog has been added.
 * A theme manager has been added to allow us to provide custom CSS for
   various themes. Currently, we have additional styling added for
   Adwaita and Adwaita-dark.