[maven-release-plugin] prepare release xwiki-core-parent-1.8-rc-1

pom.xml

xwiki-action/pom.xml

xwiki-bridge/pom.xml

xwiki-cache/pom.xml

xwiki-cache/xwiki-cache-api/pom.xml

xwiki-cache/xwiki-cache-jbosscache/pom.xml

xwiki-cache/xwiki-cache-oscache/pom.xml

xwiki-cache/xwiki-cache-tests/pom.xml

xwiki-component/pom.xml

xwiki-configuration/pom.xml

xwiki-containers/pom.xml

xwiki-containers/xwiki-container-api/pom.xml

xwiki-containers/xwiki-container-portlet/pom.xml

xwiki-containers/xwiki-container-servlet/pom.xml

xwiki-context/pom.xml

xwiki-core/pom.xml

xwiki-observation/pom.xml

xwiki-officeimporter/pom.xml

xwiki-plexus/pom.xml

xwiki-query/jpql-parser/pom.xml