[patch] gdallocationinfo read from stdin

[dangelo]

Getting information for multiple locations is often required, eg. getting heights for a set of horizontal GCPs from a DEM etc.

The attached patch reads gdal input coordinates from stdin, if they have not been supplied with the x y arguments. This way, multiple coordinates can be queried. This is especially helpful with the -valonly switch, as it can be easily used in pipes.

[dangelo]

patch v1

[warmerdam]

Patch applied in trunk (r21151).

The patch added a [-coordval] to the usage message but there was nothing else about this parameter, so I removed it.

Thanks!