[Therion] therionsurfac2survex now also on mac!

[Benedikt Hallinger]

Hi,
just wanted to drop a note that I just managed to compile the 
therionsurfac2survex tool also for mac now.
You can use it to generate a surface mesh (legs with -flag surface) out 
of GDAL or therion surface files.
This is useful if you for example want to measure distances from cave to 
surface with the help of aven.

I updated the latest release with the binary:
https://github.com/hbeni/therionsurface2survex/releases/tag/1.1.0

Have fun, and let me know if it works,
Beni