Synchronize DkML and DkCoder. Eventually dk installed by DkML and ./dk used by DkCoder will behave the same. Just like Gradle and Gradle Wrapper.

DkML 2.1.2 and 2.1.3 already released. DkCoder 0.4 is not publicly released but is available. But publicly release DkCoder 2.1.3 as part of this milestone.