Merge remote-tracking branch 'remotes/armbru/tags/pull-build-2019-07-15' into staging

Build system and documentation patches for 2019-07-15

# gpg: Signature made Mon 15 Jul 2019 20:14:38 BST
# gpg:                using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg:                issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-build-2019-07-15:
  qemu-tech: Fix dangling @menu entries
  Makefile: Fix missing dependency of on qemu-tech.texi
  Makefile: Fix "make install" when "make all" needs work

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>