Update for the ODM isNull filter to match fields that contain nulls, not just fields that don't exist. ODM documents may contain nulls via the "nullable" option. This change covers both the case where the field is null or where the field doesn't exist. isNotNull is also updated to provide the complementary behavior.
Coverage remained the same at 86.287% when pulling 8e771282c4a3829f5c124ad369be4422d34e151e on Bombdog:fix-odm-isnull-isnotnull into c5c483e512020d2964e267b219a67aa4ff41f069 on zfcampus:master.
Update for the ODM isNull filter to match fields that contain nulls, not just fields that don't exist. ODM documents may contain nulls via the "nullable" option. This change covers both the case where the field is null or where the field doesn't exist. isNotNull is also updated to provide the complementary behavior.