#329 Not all data adapter writers know about FIELD_LABEL

[Brian O.]

Issue with converting from Chado XML to other data formats:
Flat fields in the Chado XML input are stored as properties inside Apollo
prepended with the FIELD_LABEL string, e.g. <is_obsolete>0</is_obsolete> -> addProperty(feature, "field:is_obsolete", "0")

The ChadoXML writer knows to remove the FIELD_LABEL string and write the "property" out as a field, and I also put that in the GAME writer, but
other data adapter writers (including any new ones that might get written) don't know to do this, so converting from ChadoXML to other formats comes with that risk.