`version` doesn't include .0 patch versions, or suffixes (eg -gnu).
For .0 patch versions, this isn't a problem, since the glob takes care
of everything after a `.`. It does, however, prevent openafs installing
for suffixed kernels.
- Introduce new "server" output holding the server binaries
- Adapt tsmbac.patch to new build environment
- Adapt openafs nixos server module accordingly
- Update upstream CellServDB: 2017-03-14 -> 2018-05-14
- Introduce package attributes to refer to the openafs packages to use for
server, programs and kernel module
