[osis-core] Reference attribute change

[Patrick Durusau]

Guys,

Suggested attribute change on reference.

Now, targetStart, targetEnd

Proposed target and targetEnd (both are optional)

Reasoning, most software will support the initial target reference (goes 
to that starting point), better software can grab the targetEnd to make 
a fragment.

Patrick

-- 
Patrick Durusau
Director of Research and Development
Society of Biblical Literature
pdurusau@emory.edu