* Add frontend/backend make targets, fix source release
- Add 'make backend' and 'make frontend' make targets which are used to
build go and js/css/svg files respectively.
- The 'backend' target can be invoked without requiring Node.js to be
present on the system if pre-built frontend assets are present like
in the release source tarballs.
- Fix source releases missing 'dist' folders inside 'node_modules' which
were erronously excluded from tar.
- Store VERSION in file VERSION for the release tarballs and prefer that
file over git-derived version.
* fix release task
* fix typo
* fix another typo