gtsam wrapper for Chart Value

[Zhaoyang Lv]

Matlab error in testSerialization, before any fix.

Error using gtsam_wrapper
Exception from gtsam:
unregistered class - derived class not registered or exported


Error in gtsam.Values/string_serialize (line 347)
        varargout{1} = gtsam_wrapper(1125, this, varargin{:});

Error in testSerialization (line 43)
serialized_values = values.string_serialize();

[Jacob Thomson]

Adding GenericValue to the wrapper seems to fix this particular issue. However the test crashes while constructing a BearingRangeFactor2D.