element.xml patching

Currently, the build script patches element.xml to change the name parameter of Element.getElementsByTagName to tagname to make it consistent with the parameter names of Document.getElementsByTagName.  Making an actually change in the spec would be a breaking change for bindings that support named parameters and for that reason changing the spec has been rejected.  However, it simplifies things for the test suite language to have the parameter names identical.  Otherwise, both tagname and name would have to be optional attributes and use of the proper name could not be enforced by the schema.

I can move this change into dom3-combine.xsl which would eliminate the need to regenerate the patch file for subsequent versions.