Need to write unsupported projects as PE strings in HFA driver

[warmerdam]

When writing special projections like:

PROJCS["World_Cube",GEOGCS["GCS_WGS_1984",DATUM["WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.017453292519943295]],PROJECTIONCube,PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",0.0],PARAMETER["Option",1.0],UNIT["Meter",1.0]]

that are not representable by the core .img coordinate system structure should be written using the PE string structure.

[warmerdam]

Fixed in r11249 in trunk.

Test added to gdrivers/hfa.y

[warmerdam]

Back ported into 1.4 branch as r11315 along with a test in gdrivers/hfa.h.