Do not copy libwinpthread with mingw32. Needs more testing.
Do not copy libwinpthread with mingw32. Needs more testing.

msteinbeck/tinyspline,retuxx/tinyspline,msteinbeck/tinyspline,msteinbeck/tinyspline,retuxx/tinyspline,retuxx/tinyspline,msteinbeck/tinyspline,msteinbeck/tinyspline,msteinbeck/tinyspline,msteinbeck/tinyspline,msteinbeck/tinyspline