Switching the versions back to `0.x`

* Switched project version to `0.8.0-SNAPSHOT`

* Switched `log4j-changelog` XSD version to `0.2.0` (was `0.1.3`)

* Switched `log4j-changelog` XSD schema location to `log4j-changelog-0.xsd`.
  (`log4j-changelog-0.2.0.xsd` works still too, but the former is preferred.)
145 files changed