- previously always called dlclose on opened libraries when destroying
the dlLibraryTable. However, by force closing the libraries the
situation can arise that the library is missing its own code that it
needs on unload (#1524). This is also sometimes evident when closing
VTK libraries for runTimePostProcessing (#354, #1585).
- The new default is to not forcibly dlclose any libraries, unless
the dlcloseOnTerminate OptimisationSwitch specifies otherwise.
- The dlLibraryTable::close() method can be used to explicitly close
all libraries and clear the list.
- The dlLibraryTable::clear() method now only clears the entries,
without a dlclose.