* Improve the pattern to leave tagged release version numbers like
`0.2.2-alpha` alone and only increase version numbers where
git describe has added a string starting with a number.
* Add flag to display the version for each binary. It is based on `git describe` but adds
a number to the PATCH level if we are between annotated tags, so makes it semver.org
compatible. Use the "-ldflags" method that also works with go 1.17.
* Use Makefile bash and sed magic to do PATCH level increase if needed.
Co-authored-by: Bernhard Reiter <bernhard@intevation.de>
* Change mechanics to use a variable to indicate if a tag build is
wanted. Add ability to specify tag explictely.
* Use variables to have only one build recipe.
* Place binaries in target specific bin- directories.
* Do not return to main branch as it may not be the original branch we
were on. Turn this into a warning.
* "build_linux": building for GNU/linux
* "build": Building for both linux and windows (cross build)
* Place the generate binaries under "binaries/" directory
* Improve echo messages
* Makefile with the following targets
** build for (linux system)
** build_win (windows system)
** build_tag (build from the last tag)
** clean for (removing the binaries)
* Adjust README file
