moves isd creation into correct py class and adds exceptions to RasterGM (#7)

* moves isd creation into correct py class

* Adds exception handling to RasterGM.

isd.i

@@ -11,7 +11,12 @@
 
 %include <std_string.i>
 
+%pythoncode %{
+    import json    
+%}
+
 %include "Isd.h"
+%extend csm::Isd {
     %pythoncode %{
         import json
         import numpy as np
@@ -21,8 +26,6 @@
             if not isinstance(stream, dict):
                 stream = json.loads(stream)
             for k, v in stream.items():
-          if isinstance(v, np.ndarray):
-              v = v.tolist()
                 if isinstance(v, list):
                     for i in v:
                         isd.addParam(k, str(i))
@@ -32,7 +35,5 @@
         @classmethod
         def load(cls, fp):
             return cls.loads(fp.read())
-
-  Isd.load = load
-  Isd.loads = loads
     %}
+}
\ No newline at end of file

rastergm.i

@@ -4,8 +4,18 @@
 %}
 
 %ignore CSM_RASTER_FAMILY;
+%include exception.i
+%exception {
+    try {
+        $action
+    } catch (const std::exception &e) {
+        SWIG_exception(SWIG_RuntimeError, e.what());
+    }
+} 
+
 
 %import model.i
 %import geometricmodel.i
 %import csm.i
+
 %include RasterGM.h