added [] and []= als aliases for find and add

lib/polecat/storage/binary_storage.rb

@@ -36,6 +36,7 @@ module Polecat
           end # end of while
         end
       end
+      alias :[]= :add
 
       def delete key
         check_key key
@@ -96,6 +97,7 @@ module Polecat
         end
         nil
       end
+      alias :[] :find
 
       def select node = @root, &block
         if node.nil?

lib/polecat/storage/hash_storage.rb

@@ -10,6 +10,7 @@ module Polecat
         check_key key
         @storage[key] = value
       end
+      alias :[]= :add
 
       def delete key
         check_key key
@@ -32,6 +33,7 @@ module Polecat
           nil
         end
       end
+      alias :[] :find
 
       def select &block
         out = []