* gnu/packages/dav.scm (vdirsyncer): Update to 0.8.1. [native-inputs]: Add python-hypothesis, python-pytest-subtesthack.
* gnu/packages/dav.scm (vdirsyncer): New variable.
* gnu/packages/dav.scm (radicale): New file. * gnu-system.am (GNU_SYSTEM_MODULES): Add it.