* lib/filevercmp.h: New function filevercmp comparing version strings.
* lib/filevercmp.c: Implementation of filevercmp function.
* modules/filevercmp: Module metadata.
* tests/test-filevercmp.c: Unit test for new module.
* modules/filevercmp-tests: Unit test metadata.
* MODULES.html.sh: Add filevercmp module.