message: replace ospSet<> with ospSetParam
  and link to future ospray utility documentation
diff: @@ -311,29 +311,17 @@ Parameters allow to configure the behavior of and to pass data to
  objects. However, objects do _not_ have an explicit interface for
  reasons of high flexibility and a more stable compile-time API. Instead,
  parameters are passed separately to objects in an arbitrary order, and
  -unknown parameters will simply be ignored. The following functions allow
  -adding various types of parameters with name `id` to a given object:
  -
  - // add a C-string (zero-terminated char *) parameter
  - void ospSetString(OSPObject, const char *id, const char *s);
  -
  - // add an object handle parameter to another object
  - void ospSetObject(OSPObject, const char *id, OSPObject object);
  -
  - // add scalar and vector integer and float parameters
  - void ospSetBool (OSPObject, const char *id, int x);
  - void ospSetFloat (OSPObject, const char *id, float x);
  - void ospSetInt (OSPObject, const char *id, int x);
  - void ospSetVec2f (OSPObject, const char *id, float x, float y);
  - void ospSetVec2fv(OSPObject, const char *id, const float *xy);
  - void ospSetVec2i (OSPObject, const char *id, int x, int y);
  - void ospSetVec2iv(OSPObject, const char *id, const int *xy);
  - void ospSetVec3f (OSPObject, const char *id, float x, float y, float z);
  - void ospSetVec3fv(OSPObject, const char *id, const float *xyz);
  - void ospSetVec3i (OSPObject, const char *id, int x, int y, int z);
  - void ospSetVec3iv(OSPObject, const char *id, const int *xyz);
  - void ospSetVec4f (OSPObject, const char *id, float x, float y, float z, float w);
  - void ospSetVec4fv(OSPObject, const char *id, const float *xyzw);
  +unknown parameters will simply be ignored, though a warning message will
  +be printed. The following function allows adding various types of
  +parameters with name `id` to a given object:
  +
  + void ospSetParam(OSPObject, const char *id, const void *mem);
  +
  +The valid parameter names for all `OSPObject`s are discussed below. Note
  +that `mem` must always be a pointer to the object, otherwise accidental
  +type casting can occur. There also exist variants of `ospSetParam` for
  +specific types, such as `ospSetInt` and `ospSetVec3f` in the [OSPRay
  +utility library](util.md).
  Users can also remove parameters that have been explicitly set via an
  ospSet call. Any parameters which have been removed will go back to
  