File URLs will be the death of me

[Norman Walsh <nd...@nwalsh.com>]

I know this was reported (at least) once before and I couldn't
reproduce it. However, trying to reproduce the XInclude bug (I
couldn't) this morning, I tripped over the

   file://tmp/...

bug where the attempt to access that URI falls over with "unknown host: tmp".

So I dug around a bit.

I (1) consolidated several places where I was attempting to build a
URL from a filename into calls to FileURL.makeURL() and (2) tried more
aggressively in FileURL.makeURL() to make sure that file://path/ never
occurs.

Before I commit these changes, can someone else give them a whirl? If
someone on a Windows box could try too, that'd be swell. If no one
reports back, in a week or so, I'll go ahead and commit the changes.