Support for passing JVM args to runtime configuration

JVM args can now be passed from the product configuration. This change is needed in order to easily support e(fx)clipse start as an equinox application. The use case would be something like this:
````
products {
        jvmParameters << '-Dapp.address=localhost:8080/'
        jvmParameters << '-Xmx2048m'
        jvmParameters << '-Xms1024m'
        launchParameters << '-clearPersistedState'
        launchParameters << '-application'
        launchParameters << 'org.eclipse.fx.ui.workbench.fx.application'
   }
````
We cannot pass the jvm params using the -vmargs launch parameter, because it is ignored by the osgi runtime when we try to bootstrap it with e(fx)clipse dependencies.