j:not should only allow one child
conditional evaluation code
phony layer transform for onditionals
handle tei:vColl and tei:numeric
use xml:id, not jf:id for the layers
add phony layer transform to format chain
make the jf:conditional element and attributes use the same names
correct layer-id
do not remove all jf namespace attributes
update eXist to latest develop
make the reference index more index-efficient by removing 'or' logic from predicates
handle case of j:option in j:streamText
translate remaining @xml:id inside streamTexts to @jf:id during the resolve stage
allow empty inputs to common:following and common:preceding to avoid a crash (not sure if this is a good idea)
conditional evaluation in the combine transform
Merge branch 'feature/conditional-evaluation' into develop