Update inconsistent migrations documentation. Closes #4683. [machomagna@gmail.com]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4249 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

 *SVN*
 
+* Update inconsistent migrations documentation. #4683 [machomagna@gmail.com]
+
 * Add ActiveRecord::Errors#to_xml [Jamis Buck]
 
 * Properly quote index names in migrations (closes #4764) [John Long]

activerecord/lib/active_record/migration.rb

@@ -70,8 +70,8 @@ def initialize(version)
   # * <tt>change_column(table_name, column_name, type, options)</tt>:  Changes the column to a different type using the same
   #   parameters as add_column.
   # * <tt>remove_column(table_name, column_name)</tt>: Removes the column named +column_name+ from the table called +table_name+.
-  # * <tt>add_index(table_name, column_name, index_type)</tt>: Add a new index with the name of the column on the column. Specify an optional index_type (e.g. UNIQUE).
-  # * <tt>remove_index(table_name, column_name)</tt>: Remove the index called the same as the column.
+  # * <tt>add_index(table_name, column_names, index_type, index_name)</tt>: Add a new index with the name of the column, or +index_name+ (if specified) on the column(s). Specify an optional +index_type+ (e.g. UNIQUE).
+  # * <tt>remove_index(table_name, index_name)</tt>: Remove the index specified by +index_name+.
   #
   # == Irreversible transformations
   #