Can't use StAX from inside a plugins 2 plugin without embedded woodstox in the plugin.

Issue Summary

Can't use StAX from inside a plugins 2 plugin without embedded woodstox in the plugin.

Steps to Reproduce

From a v2 plugin call this:

XMLInputFactory factory = XMLInputFactory.newFactory();
factory.createXMLEventReader(new StringReader("<a></a>"));

Expected Results

The call is successful

Actual Results

You end up with:

javax.xml.stream.FactoryFinder$ConfigurationError: Provider com.ctc.wstx.stax.WstxInputFactory not found
	at javax.xml.stream.FactoryFinder.newInstance(FactoryFinder.java:154)
	at javax.xml.stream.FactoryFinder.findJarServiceProvider(FactoryFinder.java:308)
	at javax.xml.stream.FactoryFinder.find(FactoryFinder.java:233)
	at javax.xml.stream.XMLInputFactory.newFactory(XMLInputFactory.java:156)
	at com.atlassian.jira.dev.functest.ao.BlogResource.getAll(BlogResource.java:91)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at com.atlassian.plugins.rest.common.interceptor.impl.DispatchProviderHelper$ResponseOutInvoker$1.invoke(DispatchProviderHelper.java:206)
	at com.atlassian.plugins.rest.common.interceptor.impl.DispatchProviderHelper$1.intercept(DispatchProviderHelper.java:90)

Notes

• JIRA ships with wstx-asl-3.2.4.jar (Woodstox) in WEB-INF/lib. This JAR registers itself with the JVM to provide implementations of XMLInputFactory, XMLOutputFactory and XMLEventFactory from its META-INF.services. Basically, once we put this JAR in WEB-INF/lib we end up with com.ctc.wstx.stax.WstxInputFactory, com.ctc.wstx.stax.WstxOutputFactory and com.ctc.wstx.stax.WstxEventFactory being the default implementations of these classes.
• The problem is that we don't expose the wstx-asl-3.2.4.jar classes to plugins even though we expose its META-INF.services (we boot delegate META-INF.services)).
• The solution is NOT to simply add the wstx-asl to the packages that we expose to plugins (what happens we change the JAR and replace with a different implementation?).

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available