tmpfiles: add "+" modifier support to b, c, p lines in addition to L
namespace: properly label device nodes we create

https://bugzilla.redhat.com/show_bug.cgi?id=1081429
update TODO
tmpfiles: w lines should allow following symlinks
tmpfiles: create directories already with the right label, instead of creating them first, and relabeling them afterwards
cryptsetup: introduce new cryptsetup-pre.traget unit so that services can make sure they are started before and stopped after any LUKS setup

https://bugzilla.redhat.com/show_bug.cgi?id=1097938