Support Saxon's simpler ExtensionFunction interface in addition to ExtensionFunctionDefinition.
Used a star import - oops.
Merge pull request #69 from jamesrdf/memory-leak-functions

Memory leak in extension functions
Merge pull request #67 from jamesrdf/http-request-systemId

Fix systemId for redirected HTTP requests in p:http-request
Merge pull request #62 from argv-minus-one/saxon94

Support Saxon 9.4's ExtensionFunction interface for extension functions
Merge pull request #68 from jamesrdf/multiple-saxon-processors

Allow multiple saxon processors to be used
Merge pull request #5 from ndw/saxon94

Merge upstream changes