build.xml updated for recent L3 working drafts

I updated build.xml to point to the recent working drafts.  The core and events drafts did files (text and textevent) that had been omitted in the previous working drafts.  I should be able to do an updated dom3.xsd and dom3.dtd this weekend.

However, there will still quite a few missing entity declarations.  Starting at line 1415 there are three patches that are only necessary to add the missing entity declarations.  In a perfect world, the next WD's would not require these patches.

p.s. the element patch changes the parameter name on getElementsByTagName so the two forms are in synch and does not correspond to an flaw in the xml sources.