Use elfin built back from JSON serialisation to file.
Added test demonstrating problem with missing number value.
Added to solve XML data with missing Z coordinate in POINT:
geoXml.xsd definition: 
<xs:attribute name="Z" default="0" type="xs:double" use="optional">
Expected scalaxb data is either default="0" or provided but not missing.
The serialisation fails if there is no Z value.
Back to original state. Problem is with ANGLES attribute not containing
valid type="xs:double" but "NaN" string value.
Removing Elfin model object and related tests. This has been replaced by
ELFIN and other model objects located in
ch.bsisa.hyperbird.model.geoXml.scala file.