[QGIS-Developer] Request for freeze exemption: datum transform handling

[Nyall Dawson]

Hi all,

I would like to request an exemption from the feature freeze in order
to merge https://github.com/qgis/QGIS/pull/5535 and a future follow up
by Denis which will address the GUI component of that work.

Because of the heavy API breakage that this PR involves, it needs to
be merged before API freeze. I also consider this a crucial
"must-have" for QGIS 3.x, given that it sets in place a framework
which is required for features that will become highly in-demand
during the lifetime of 3.x (namely - support for dynamic datum
transforms.... without this, QGIS will become a non-option for
Australian users in 2020).

Not to put to much emphasis on this, but this is a kind of
"make-or-break" decision, where not fixing this part of the API could
really slow QGIS' current growth rate and force our users to use
alternative programs.

Nyall