Previously, there was no addJava function defined in the ash-template.
This resulted in warnings when the ash script ran because template
declares expects the function to be defined.

Now, the addJava function is defined. It adds options to java_opts. As a
convenience, if JAVA_OPTS is set then it is added to java_opts. This
makes the ash script behave more like the bash script. The result is
then passed to java at the end of the script.