ENVI .hdr file parsing

[verosk]

Some legacy software produces .hdr files with fields separated by '\t' (in addition of standard space '\x20').

Although ENVI can read such files without problems, GDAL refuses because of invalid header ,

The file appears to have an associated ENVI header, but
one or more of the samples, lines, bands and interleave
keywords appears to be missing."

I suggest applying attached patch to GDAL core to make reading of ENVI .hdr more robust.

--Veros

[verosk]

Robust .hdr reading patch

[warmerdam]

Approximation of patch applied without the wavelength metadata change. Done in trunk (r20530).

[verosk]

I'm sorry I mixed two patches (other part is patch for #3682).

--V