Updated the breaking changes doc to include recent increased unique_ptr usage

BREAKING-CHANGES.txt

@@ -4,6 +4,27 @@ JUCE breaking changes
 Develop
 =======
 
+Change
+------
+JUCE is moving towards using C++11 pointer container types instead of passing
+raw pointers as arguments and return values.
+
+Possible Issues
+---------------
+You will need to change your code to pass std::unique_ptr into and out of
+various functions across JUCE's API.
+
+Workaround
+----------
+None
+
+Rationale
+---------
+Indicating ownership through the transfer of smart pointer types has been part
+of mainstream C++ for a long time and this change enforces memory safety by
+default in most situations.
+
+
 Change
 ------
 SystemTrayIconComponent::setIconImage now takes two arguments, rather than one.