[DAS2] duplicate use of VERSION

[Andrew Dalke]

Brian G. pointed out that "VERSION" is used twice in the spec,
with different meanings.

I thought we used it twice as an element but that's not the
case.  It's used once as "versioned source" element and another
time as an attribute in the COORDINATES element

   # This is the version of the build (if a genomic sequence).
   # However, protein databases don't do versions this way
   attribute version { text }?,

In looking around I don't see duplicate uses of any tag for
elements with different meanings.

Brian?  Is this the one you were talking about?

In thinking about it though, I've found it awkward to talk
about "versioned source".  First off, the Mac's Mail.app gives
squiggles under the "versioned" indicating a misspelling.
Second, it's hard to say and annoying to write "versioned_source"
in my code and in the documentation.

I would like to use "release" instead.  That is, change
das2:VERSION to das2:RELEASE.  That's a shorter word, closer
to the intended meaning, and generally nicer.  Eg, "there are
many data sources and each source may have multiple releases."

That's a simple change but it's highly non-backwards compatible.

					Andrew
					dalke at dalkescientific.com