preferable to use the existing 'undo-inhibit-region' symbol property
instead of this variable.
+** Function type declaration
+It is now possible, using the 'declare' macro, to declare expected types
+of function arguments and return type.
+
** New types 'closure' and 'interpreted-function'.
'interpreted-function' is the new type used for interpreted functions,
and 'closure' is the common parent type of 'interpreted-function'