Add support for calling ggplot/R directly in GRAAL VM

[apatrida]

see: https://medium.com/graalvm/enhance-your-java-spring-application-with-r-data-science-b669a8c28bea

[holgerbrandl]

That's such a great pointer. Thanks for sharing. :-)

I wonder in particular if this would somehow allow to bundle R as a jar-dependency for kravis. I've tried to build such a jar including R itself in a multi-OS manner some time ago, but failed miserably because R seemed to use absolute paths all over the place.