Arithmetic broken for G3 numeric types

[ndhuang]

G3 numeric types (and their vector equivalents) all seem to have some broken arithmetic operations, either with numpy and python scalars, or even with themselves. Here is a sampling of things that raise TypeError: unsupported operand...:

G3Int + G3Int
int + G3Int
G3Int + int
G3VectorInt + int
G3VectorDouble + G3VectorDouble
float * G3VectorDouble
float + G3VectorDouble
G3VectorDouble + float
G3VectorComplexDouble * float

Notably, the follwing do work:

np.float64 * G3VectorDouble
G3VectorDouble * np.float64
G3VectorDouble * float
G3VectorComplexDouble * float64

[arahlin]

I suspect this is not easy to resolve. You can work around the issue by using np.asarray() on G3VectorInt and G3VectorDouble objects for now, since the result is a view on the underlying shared memory buffer.