Add support for -Xnosplash

[akuhtz]

It would be nice to have support for the -Xnosplash option in OpenWebStart from here: https://docs.oracle.com/javase/8/docs/technotes/tools/unix/javaws.html

See also AdoptOpenJDK/IcedTea-Web#420

[akuhtz]

Update:
javaws -Xnosplash -jnlp http://localhost:8080/webstart/foo.jnlp
while
javaws -Xnosplash http://localhost:8080/webstart/foo.jnlp
fails.

In the itw-javantx-...log I see that the args -verbose, -jnlp are added before the -Xnosplash
and it seems that the -jnlp at this location causes the error.

ITW Boot called with custom OwsJvmLauncher and args [-verbose, -jnlp, -Xnosplash, -jnlp, http://localhost:8080/webstart/foo.jnlp].

[sclassen]

fixed with OWS 1.1