* Move classes from mapstruct-common into mapstruct
* Use Java 8 @Repeatable for @Mappings and @ValueMappings in the mapstruct module
* Add relocation for mapstruct-jdk8 to mapstruct
* Use of 1.8 source and target versions from parent POM
* Update documentation to match
* Update versions of some maven plugin crashing build on Java 8
* Drop JDK 6 & 7 support in integration tests
* Remove mapstruct-common module (it was never deployed to Central)