Set cmake dependencies on individual libraries.

While this change might cause a bit of redundancy on the final link
line, it should make things clearer. Also, if we change the static
libraries to shared libraries, then we won't need to modify the
dependencies then either.
Enable building of sps test program.

I'm not sure whether it actually does anything useful right now, though.
Fix build of OpenInventor conversion programs.

This adds an optional dependency on Coin3D, an open source
implementation of Open Inventor. I don't know if there are others, but
this seems to be the only one with a builtin CMake test.
Use standard STL headers everywhere.

There used to be wrappers that included versions either with or without
extension, but it seems no-extension is used all over the place.
Whatever compiler required the old-style headers is probably not that
important anymore.
Remove unused _events from BaseJOTapp class.
Silence parentheses warning.

I don't know if this way is the intended way, but it's the way that the
compiler would use in the end.
Remove unused WarnOnce class.