himitsu 0.7

This release fixes a bug, where the himitsu store is cleared when trying
to delete an empty key.

Armin Preiml (3):
      secstore: strict query support for delete
      docs: add -s to hiq synopsis
      secstore: do not allow adding empty entries

Lennart Jablonka (3):
      don't depend on keystore::key's underlying type
      Makefile: don't use $< in non-suffix-rules
      himitsud: use self-pipe instead of signalfd