* targets.mk: If $(ORGVERSION) and $(GITVERSION) are not defined and
cannot be determined from Git, try to read `version.mk´. Fall back
to "N/A" if still no definition has been made.
* utils/server.mk: Create `version.mk´ for each distribution. Append
"-dist" and "-elpa" to $(GITVERSION) to easily recognize builds from
distribution archives. Remove `version.mk´ in `cleanrel´ and use
the same globbing patterns as .gitignore.
* .gitignore: Add "version.mk", also ignore ELPA archive (no ".gz"
suffix) and only "org-version.el" (no globbing).
ee9e27e66e