Clean up tamas's recent commit and update CHANGELOG

This is a potential breakage of backwards compatibility, but it's
unlikely that anyone would be relying on changed_columns being empty
in an after filter, or new? always returning false even the record
being saved was new.  With this commit, it's easier to code a complex
after_save that needs to differentiate between a freshly inserted
record and one that was updated (instead of using a separate
after_create and after_update filters), or have your after_update
filter act depending on contents of changed_columns (previously,
saving them to a separate instance variable in a before_update
filter was the best way).

CHANGELOG

@@ -1,5 +1,7 @@
 === HEAD
 
+* Don't modify Model#new? and Model#changed_columns when saving a record until after the after hooks have been run (tamas, jeremyevans)
+
 * Database#quote_identifiers= now affects future schema modification statements, even if it is not used before one of the schema modification statements (jeremyevans)
 
 * Fix literalization of blobs when using the PostreSQL JDBC subadapter (jeremyevans)

lib/sequel_model/record.rb

@@ -212,12 +212,12 @@ def save!(*columns)
           if (pk = primary_key) && !(Array === pk) && !@values[pk]
             @values[pk] = iid
           end
-          if pk
-            @this = nil # remove memoized this dataset
-            do_refresh = true
-          end
+          @this = nil if pk
         end
         after_create
+        after_save
+        @new = false
+        refresh if pk
       else
         return save_failure(:update) if before_update == false
         if columns.empty?
@@ -227,15 +227,13 @@ def save!(*columns)
           this.update(@values.reject{|k, v| !columns.include?(k)})
         end
         after_update
+        after_save
+        if columns.empty?
+          changed_columns.clear
+        else
+          changed_columns.reject!{|c| columns.include?(c)}
+        end
       end
-      after_save
-      if columns.empty? || new?
-        changed_columns.clear
-      else
-        changed_columns.reject!{|c| columns.include?(c)}
-      end
-      @new = false
-      refresh if defined?(do_refresh) && do_refresh
       self
     end