Bring back changelog entries for Active Support

Removed in 0228a73b, pull request #7310.

activesupport/CHANGELOG.md

 ## Rails 4.0.0 (unreleased) ##
 
+*   ActiveSupport::JSON::Variable is deprecated. Define your own #as_json and
+    #encode_json methods for custom JSON string literals.
+
+    *Erich Menge*
+
+*   Add String#indent. *fxn & Ace Suares*
+
+*   Inflections can now be defined per locale. `singularize` and `pluralize`
+    accept locale as an extra argument.
+
+    *David Celis*
+
+*   `Object#try` will now return nil instead of raise a NoMethodError if the
+    receiving object does not implement the method, but you can still get the
+    old behavior by using the new `Object#try!`.
+
+    *DHH*
+
 *   `ERB::Util.html_escape` now escapes single quotes. *Santiago Pastorino*
 
 *   `Time#change` now works with time values with offsets other than UTC or the local time zone. *Andrew White*

activesupport/lib/active_support/core_ext/object/try.rb

@@ -37,7 +37,7 @@ def try(*a, &b)
       public_send(*a, &b) if respond_to?(a.first)
     end
   end
-  
+
   # Same as #try, but will raise a NoMethodError exception if the receiving is not nil and
   # does not implemented the tried method.
   def try!(*a, &b)
@@ -63,7 +63,7 @@ class NilClass
   def try(*args)
     nil
   end
-  
+
   def try!(*args)
     nil
   end