[Geotiff] Add support for TIFFOpenStream

[Fred Rothganger]

Frank Warmerdam wrote:
>>    2) Make _XTIFFInitialize() public.  Since this is the only thing 
>> special about the XTIFFOpen() functions, it is just as simple to 
>> allow the client code to call it, and then use whatever TIFFOpen it 
>> wishes.
>
> Feel free to submit a bug report with the patch to make this public and
> I will incorporate it.


Frank,

    I submitted bug report #1296 with the patch attached.  Could you
look at and see if it can be applied?  This would really be helpful to
me, because I am preparing my software for release, and would really
like to avoid shipping a specially modified library with it.

-- Fred