Download com.vertispan.jsinterop JAR files with all dependencies

Base classes and utilities that provide access to JavaScript language constructs that are not available in pure Java. This distribution is slightly modified from the original in order to be compatible with J2CL and, where possible, GWT2 (though this is not heavily tested). The links and references in this pom.xml will reference the Vertispan fork, to ensure that any error introduced by our changes are not incorrectly blamed on the upstream Google repository.