#446 @schemeVersion should be added to specify the version of a style scheme

[Martin Holmes]

~~~~~~~~~~~
@scheme on <rendition> and <styledefdecl>
(which should eventually be a class, perhaps
att.styleScheme) does not enable the specification
of which version of e.g. CSS is being used. Addition
of @styleScheme to this class or these elements
would allow that. See discussion on Council list.
~~~~~~~~~~</styledefdecl></rendition>

Also see https://sourceforge.net/p/tei/bugs/539/.

[Martin Holmes]

In rev 11877:
Added new @schemeVersion to att.styleDef, including a Schematron constraint to ensure that if it's used, @scheme is also used, and included the new attribute in a couple of examples. Still to do:

• Tests for the schema constraint;
• Adding <rendition> to att.styleDef and removing its locally-defined @scheme;
• Changing the datatype to Lou's proposed data.versionNum once this is available.

[Martin Holmes]

Tests for Schematron constraint added in revs 11882 ff.