add python version for getA/getb as cython can't convert constABlock/BVector to Matrix/Vector automatically.

gtsam/linear/JacobianFactor.h

@@ -268,9 +268,11 @@ namespace gtsam {
 
     /** Get a view of the A matrix, not weighted by noise */
     constABlock getA() const { return Ab_.range(0, size()); }
+    Matrix py_getA() const { return getA(); }
 
     /** Get a view of the r.h.s. vector b (non-const version) */
     BVector getb() { return Ab_(size()).col(0); }
+    Vector py_getb() const { return getb(); }
 
     /** Get a view of the A matrix for the variable pointed to by the given key iterator (non-const version) */
     ABlock getA(iterator variable) { return Ab_(variable - begin()); }