Conditionally removes usage of deprecated features

-add macros to test for C++ version and features
to catch_compiler_capabilities.hpp
- replaces dynamic exception specifications (deprecated)
with noexcept in C++ Version >= 11
- defines defaulted copy constructor/move constructors/assignment
in C++ Version >= 11 since their implicit generation is deprecated
under some circumstances.
- fixes #259

include/internal/catch_xmlwriter.hpp

@@ -66,11 +66,18 @@ namespace Catch {
                 endElement();
         }
 
+#  ifndef CATCH_CPP11_OR_GREATER
         XmlWriter& operator = ( XmlWriter const& other ) {
             XmlWriter temp( other );
             swap( temp );
             return *this;
         }
+#  else
+        XmlWriter( XmlWriter const& )              = default;
+        XmlWriter( XmlWriter && )                  = default;
+        XmlWriter& operator = ( XmlWriter const& ) = default;
+        XmlWriter& operator = ( XmlWriter && )     = default;
+#  endif
 
         void swap( XmlWriter& other ) {
             std::swap( m_tagIsOpen, other.m_tagIsOpen );