* Fixed compiler warning -Wdeprecated with clang.

Starting with C++11 implicit copy-constructors are deprecated when the class
has a user defined destructor.

* Fixes -Wdocumentation warning.

yaml-cpp/parser.h:50:65: warning: parameter 'eventHandler}.' not found in the function
      declaration [-Wdocumentation]
   * Handles the next document by calling events on the {@param eventHandler}.
                                                                ^~~~~~~~~~~~~~
yaml-cpp/parser.h:50:65: note: did you mean 'eventHandler'?
   * Handles the next document by calling events on the {@param eventHandler}.
                                                                ^~~~~~~~~~~~~~
                                                                eventHandler