ISPN-4948 Fixed version
ISPN-4961 Bump parsers and schemas to 7.1

- Altered org.infinispan.Version to retrieve the version using
maven-injection-plugin
- Improved SampleConfigFilesCorrectnessTest so that it accepts only
files with the latest schema
- Altered the documentation so that the version is dynamically replaced
- The Soft-Index File Store schema namespace was missing the "store" path
element. Added it for symmetry with all other store schemas.