[netcdf-java] NcMLWriter support for values

I wanted to enable <values> output in an ncml dump, say in NcMLWriter or at least provide a custom writer that possibly re-uses NcMLWriter.
On determining whether to output values, NcMLWriter does a Variable.isMetadata() check, so I went looking for a hook here. Unfortunately there is no setIsMetadata method on VariableIF, no ability to do "Variable.isMetadata = true" (it's protected) and no way to over-ride NcMLWriter.writeVariable (it's private with no public api exposure).
So basically I need to code a new writer class - I just mention this because NcMLWriter really needs fixing up (plus no interface etc - ncml is useful!). 

Thanks, Nick