Add ability to configure global JAXP schema source locations

• User impact:

  Medium
• Affects Docs:

  Yes
• Similar Issues:

  None

In the spirit of having a global namespaces manager, a similar concept should be applied to JAXP schema sources. At the moment one has to declare them inline (where it is possible, but not everywhere), and not every element then supports multiple schema locations config.

Provide a global way to configure JAXP schema locations in Mule config and update splitters, filters, etc to use it when available.

Implementation notes:

• Original discussion: http://www.nabble.com/Accessing-resource-inside-a-jar-file-td21807218.html