[eclipselink-dev] Fix for bug 218047

[Matt MacIvor <matt.macivor@xxxxxxxxxx>]

Hi all,

Please review the patch for this bug at the below location:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=218047

Overview:

With the native metadata schema being introduced in BUG 200040 the issue of
namespace resolving has introduced a loading problem.

We currently want EclipseLink to load a JPA orm.xml and an EclipseLink orm.xml
against the same MOXy mapping project.

The namespace resolver must be set on the MOXy mapping project and currently
only one project may be added to the XMLContext used to unmarshal the xml
document. 

If the XMLContext allowed for a list of projects to be added, EclipseLink's JPA
loading could then instantiate the MOXy mapping file twice, each with its own
namespace. From discussions with the EclipseLink MOXy team the unmarshaller
would then be able to determine the correct project file to use to unmarshal
the document.

-Matt