CS_gpdefEx doesn't care if a path is reversible

[ravenAtSafe]

CS_gpdefEx doesn't check whether a path is reversible before accepting it as a valid answer.

Which is probably for the best as the 'cs_GeodeticPath_.reversible' member variable is always left as '0'.

Probably the definition compiler should be setting that flag?

[baertelchen]

Will be touched / changed due to the implementation of RFC 6.

Assigning to me.

[Norm Olsen]

Corrected at version 2706. Modified the Geodetic Path compiler to properly set the 'reversible' path definition data element, and adjusted the path serach function in CS_gpio.c to skip looking for a path in the reverse direction if the path is notmarked as reversible. Note, that conversions between Reunion47 and WGS84 are not reveersible and represent good test cases.