and remove "release" from the enum tag names.
no functional change, however, despite the addition of
backwards-compatibile declarations in this patch, it is breaking because
expressions that use `==` or `!=` operators will not able to use the
deprecated names.
I predict these names to survive until the 1.0 tag without any more
breakage.
This "get" is useless noise and was copied from FixedBufferWriter.
Since this API has not yet landed in a release, now is a good time
to make the breaking change to fix this.