JSword needs to work with SWORD standard OSIS Variants

SWORD has defined a standard mechanism for identifying Biblical variants of the form <seg type="x-variant" subType="x-n">...</seg> where n is a number from 1 to max number of variants (so far a max of 2 variants) and where 1 is the default variant.

Note, the old ThML module WHNU is now an OSIS module. JSword had variant support for that module. The upgrade to OSIS broke JSword. For that reason it is a bug and not a feature request.

Also note, the bug fix is a one line change in JSword and a corresponding change in BibleDesktop's simple.xsl.

It'd also be good to add the ability to switch between variants. This has been added to simple.xsl as a parameter named Variant. The corresponding change needs to be made in JSword.