build: use VERSION_SHORT instead of VERSION_STRING

We have recently changed VERSION_STRING to append CONFIG_RC at the
end of the string. Thus, for the build system, change it to
VERSION_SHORT where needed, e.g. in release targets where the "+"
appendix is not wished.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
build: tag: add 'v' prefix for tag name

We need to add a 'v' prefix to the actual version for the tag name.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
build: fix up GIT_PEOPLE and GIT_LOG macros

Fix them up so that a proper changelog can be generated automatically.
Also while at it, add two "hidden" targets that can be used to test
their output.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
build: fix up announce message in announce target

Bring the announce message in line with the latest released announce
message from rc1. So that in future this can be generated automatically.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>