[Xastir] [tiling] reading tiles slow

[Jason KG4WSV]

I suspect xastir uses its own projection because a) it's easier, and
b) it supports so many different formats, it makes as much sense to
convert to an internal easy-to-use format as anything else.

I wonder if there's a reasonably efficient way to convert the tiles to
xastir projection (or a projection that xastir can crunch quickly).
If the tiles are going to be cached or otherwise re-used, that
complexity and computation cost may make sense.

-Jason
kg4wsv