Add CapsuleShape and ConeShape

[jslee02]

This pull request adds two new shape classes: CapsuleShape and ConeShape. Currently, only BulletCollisionDetector support the shapes. Both of OpenGL and OSG based renderers display the shapes. Also, these shapes can be parsed from SKEL file format. Here is part of an example skel file that contains the new shapes:

<visualization_shape>
    <geometry>
        <capsule>
            <height>0.1</height>
            <radius>0.05</radius>
        </capsule>
    </geometry>
</visualization_shape>

<visualization_shape>
    <geometry>
        <cone>
            <height>0.1</height>
            <radius>0.05</radius>
        </cone>
    </geometry>
</visualization_shape>

Additional changes: A syntactic sugar function Shape::is<SHAPE_TYPE>() is added that enables us to check the shape type from a Shape pointer in more convenient way. Here is a short example code:

auto shape = bodyNode->getShapeNode(0)->getShape();
if (shape->is<BoxShape>())
  std::cout << "The shape type is box!\n";

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This change is