ARELLE-298: EFM changes
6.5.9/.10 old behavior unless edgartaxonomies.xml has Erxl version="27"
or higher, then new behavior (1 day periods are ok, instants ok everywhere)
6.5.37 (insignificant digits considering decimals on number)
6.5.38 (no forever periods)
6.7.31 (no fraction concepts)
6.10.9 (numeric label role on nonnumeric concept)
fact decimals limited to -28 <= decimals <= 28 (no error or warning)
schema validation regression (found in 6.5.9), due to inline updates, fixed
(some ModelFormula objects had qname methods overriding schema qname)