The input file includes <coordinate> elements of the form
<coordinate>
aaa,bbb,ccc
ddd,eee,fff  ggg,hhh    jjj,kkk,lll
</coordinate>

of which the content, when left and right stripped, is a
whitespace-separated sequence of points; each point
being a comma-separated sequence of either two or three numbers.

All <coordinate> elements are to be replaced, in the output file, by
elements of the form:

<FullCoordinates datum="WGS84" >
 <Point longitude="aaa" latitude="bbb" ht_above_geoid="ccc">
 <Point longitude="ddd" latitude="eee" ht_above_geoid="fff">
 <Point longitude="ggg" latitude="hhh">
 <Point longitude="jjj" latitude="kkk" ht_above_geoid="lll">
</FullCoordinates>