[PROJ] PROJ grid files CDN

[Jeff McKenna]

> Bit late to this thread, sorry. While I think the proposal will be
> very useful in some circumstances, it's not a fix-all and it's still
> going to be very important for client applications to warn their users
> whenever a grid is desirable but not available and provide some
> user-friendly method to do this.
> 
> I'm thinking specifically of offline users here, or those with
> unreliable/expensive internet connections. For these users it's
> critical that they are alerted about missing grids instead of just
> silently falling back to an inferior operation.
> 
> And we should also consider releasing all-in-one packages of end user
> applications which include ALL the datum grid packages, so that users
> who require an offline installer will be guaranteed to have these
> available... (again, thinking of someone who goes out to the field in
> a remote location without regular internet connections).
> 
> Nyall
> 
I feel the same as Nyall, that users of PROJ need to be alerted when a 
grid file is missing.

In the case of MS4W, I package all of the grids for Windows users, since 
there is no notification for Windows users who lack those files.  I 
think once the warning/notice is implemented, this will mean packagers 
like me won't have to package all of the grid files anymore, since users 
will be notified and can then download the files themselves.

-jeff