Point Feature stack fails to process datasets with multiple lat/lon axes

[cwardgar]

To reproduce, go to the ToolsUI PointFeature panel and try to open cdm/src/test/data/cfDocDsgExamples/H.2.3.2.ncml, which is example H.5 from the CF DSG doc. You'll get:

java.lang.IllegalArgumentException: illegal member name =precise_lat

Note that we can open H.4 (the previous example) just fine, and the only difference between the two is the addition of precise_lat and precise_lon. Clearly we're not handling the additional lat/lon axes properly.