The check if ( subdevice != -1 ) was being done on a potentially
uninitialized variable.

Use free() for allocated memory by calloc (not delete).
Deleting calloc-ed memory will become problem in the environment which
overrides global "operator delete" like some game engine.

Without algorithm header, Visual Studio complaints that std::max is not
declared and defined.
Including algorithm header resolves this issue.

Deleted RtError.h from distribution and renamed all references to
RtError in the documentation, test files, and Windows .dsp files.
The version number was incremented to 4.1.0 in anticipation of
the next release, as this change affects the API.