downloads:
 https://github.com/ericwa/tyrutils-ericw/releases/tag/ericw-v0.15.10
 
 - light: add "_shadowworldonly" bmodel key - only cast shadows on world, not other bmodels.
 - light: switchable bmodel shadows (requires QuakeC support, see light manual).
 - light: accept "_minlight" in worldspawn as an alias for "light"
 - light: handle degenerate faces, print out the vertex coordinates
 
 - qbsp: misc_external_map prefab system (see qbsp manual)
 - qbsp: don't write unused texinfo
 - qbsp: rewrite outside filling similar to q3map
 - qbsp: revert change to SubdivideFace which was increasing faces a bit (see 53743dd)
 - qbsp: add -expand option to dump the hull expansion to a "expanded.map", from q3map
 - qbsp: add -leaktest option to abort compilation when a leak is found, from qbsp3
 - qbsp: fix handling of duplicate planes, which was causing id1 maps to leak
 - qbsp: try to get more reliable leaf content assignment (see a910dd8)
 
 - bsputil: --check: print BSP tree heights at the first few levels of the tree
 - bsputil: --check: check for unreferenced texinfo, vertices, planes
 - bsputil: --check: print number of used lightstyles
 - misc: travis-ci now runs qbsp on all id1 maps, the build fails if any maps leak