remove requirement that reading systems are conforming xml:base processors - #1678

2. xml:base in package document and elsewhere

See github issue #1456.

Dave Cramer: XML base
… Have a pull request to remove a line

See github pull request #1678.

Dave Cramer: xml base is disappearing from the world at large
… It isn't forbidden, but not a useful requirement to support it
… Authors shouldn't do it, and we should make it so RSes shouldn't support it in the future

Proposed resolution: dump xml:base from the spec (Ivan Herman)

Brady Duga: +1

Dave Cramer: +1

Gregorio Pellegrino: +1

Toshiaki Koike: +1

Bill Kasdorf: +1

Masakazu Kitahara: +1

Ben Schroeter: 0

Dan Lazin: +1

Matt Garrish: +1

Resolution #2: dump xml:base from the spec