Comment 1 for bug 1400254

Hugin is using libpano13 for all the remapping. So the projection have to be added to libpano13.

I see at least 2 issue with this projection:
* Blending about the 360 deg border in this projection is not not supported by enblend/smartblend/multiblend. So this projection needs a special treatment for the 360 deg case.
* Even when the projection has less distortion than equirectangular, there are 4 singularities, and all are at the equator (and so in the middle).