[python][point] implement type deduction from args

python/frackit/geometry/__init__.py

 from ._geometry import *
+
+# Construct an n-dimensional point
+def Point(*args, **kwargs):
+
+    numArgs = len(args) + len(kwargs)
+    if numArgs == 0:
+        raise Exception("Arguments needed for point construction. For default-" + \
+                        "constructible points use the dimension-specific " + \
+                        "implementations Point_1, Point_2 or Point_3");
+
+    # single argument construction
+    if numArgs == 1:
+        # construction from a list
+        if isinstance(args[0], list):
+            if len(args[0]) == 1: return Point_1(*args, **kwargs)
+            elif len(args[0]) == 2: return Point_2(*args, **kwargs)
+            else: return Point_3(*args, **kwargs)
+        # construction from a single (hopefully) scalar
+        else: return Point_1(*args, **kwargs)
+
+    # select point type from the number of arguments
+    if numArgs == 2: return Point_2(*args, **kwargs)
+    else: return Point_3(*args, **kwargs)