Complete release notes
Update propdeps, pitest dependencies
Update to gradle 2.2
Update runtime and test dependencies

Guava, asm, testng, mockito, assertj, etc
Fill release notes
Small javadoc fix
build.gradle: make name, description appear in generated pom

Adapted from similar fix in json-patch.
build.gradle: no need to refer to maven snapshots anymore

We use stable versions of pitest.