Prototype for ccScalarField constructor changed

NOTES:

* I also changed "Intensity" to CC_SCAN_INTENSITY_FIELD_NAME
* "Time" and "Return Number" do not have #defines that match exactly - should they be added?
* All these ccScalarFields were constructed asking for negative values not to be ignored - are they going to do the right thing now?  I followed the example in E57 which just eliminated the boolean argument