typeToString raises for the OWL_DOUBLE types #27

typeToString in owl/Object.cpp has no cases for OWL_DOUBLE, OWL_DOUBLE2, OWL_DOUBLE3 and OWL_DOUBLE4, so it ends up in the default branch and raises:

std::string owl::typeToString(OWLDataType): not yet implemented for type #1052

It is mostly called while building error messages, for example "trying to set variable to value of wrong type" in Variable.cpp, so with a double variable that error is replaced by the one above. sizeOf got the double types in #26, and Variable.cpp already handles them, so this is the last switch that misses them.

I have a small fix ready and will open a PR for it.