[El] BigTiff

[Mathieu Baudier]

> BigTIFF support will require libtiff 4 (beta).  I see currently a rather
> antique libtiff is being used.   Note that the libtiff4 ABI is different
> than libtiff3.

Yes, I remember giving it a try some months ago when we started the
project, and facing the issue that the base libtiff was to old.

It is of course possible to go down the dependency list and package a
recent version of libtiff, etc. as we have done for other packages.
But in that case we have to be careful that GDAL is in elgis "pure"
(that is non "plus": it does not require to update the base
distribution), so if we add a dependency, it should not conflict with
base:
- it should be named libtiff4
- potential conflicts if both libtiff and libtiff4 are installed
together should be isolated

I won't have time to work on this, but contributions are of course
always welcome.

There may be a good case here for booking a Trac ticket since this
issue is not trivial.