Requires FGData commit: 0565eaab10a5d466cd485766b17d1870936a0a57
(which actually renames the file).
Also disables the preferences-load command since I don’t believe it
would actually be safe to reload the defaults without doing a simulator
reset (aircraft -set.xml values would be overwritten, for example)
Add option --print-solidness
without this option, behaviour of fgelev is unchanged
with this option the word "solid" gets printed behind the elevation if the
material at the given location is solid. A hyphen (-) gets printed otherwise
Remove uses of .str(), .c_str() and some other methods of SGPath.
Pass SGPath directly where possible, or explicitly convert to the
appropriate 8-bit encoding.
default of 10 if given.
This improves performance _a lot_ if massively probing across
a bucket border as it prevents constant terrain unloading/reloading.
Adapt to corresponding SG change to make SGMaterialLib be ref-counted,
and have the 'reload-materials' command notify the tile-manager of this,
so it can update the options struct it passes to new tiles.
