Upgraded hibernate-core, hibernate-envers, hibernate-validator and maven-core

 * Upgraded hibernate-core      from 4.3.1.Final to 4.3.7.Final
 * Upgraded hibernate-envers    from 4.3.1.Final to 4.3.7.Final
 * Upgraded hibernate-validator from 4.3.1.Final to 4.3.2.Final
 * Upgraded maven-core          from 3.2.1       to 3.2.3
Upgraded hibernate-validator from 4.3.2.Final to 5.1.3.Final

Hibernate Validator 5 requires the Unified Expression Language (EL) in
version 2.2 or later. Therefore, a dependency to javax.el-api:3.0.0 was
added. (Without that, the compilation of some integration-tests fails!)