towgs84 param is missing for NTF datum in ecw_cs.wkt

[clb33]

No information concerning the datum shifting are included for the NTF datum.

NTF,GEOGCS["N.T.F.",DATUM["NTF",SPHEROID["CLA80IGN",6378249.2,293.4660213]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433]]
NTFPARG,GEOGCS["N.T.F",DATUM["NTFPARG",SPHEROID["CLA80IGN",6378249.2,293.4660213]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433]]
NTFPARIS,GEOGCS["N.T.F",DATUM["NTFPARIS",SPHEROID["CLA80IGN",6378249.2,293.4660213]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433]]

The TOWGS param is : TOWGS84[-168,-60,320,0,0,0,0]

I've attached a patch with this parameter.

[clb33]

patch proposal

[Even Rouault]

Commited in trunk (r26133)