Update docs. Remove old classes.doc.

Demo/classes/README

@@ -10,5 +10,4 @@ Vec.py		A simple vector class
 bitvec.py	A bit-vector class by Jan-Hein B\"uhrman
 
 (For straightforward examples of basic class features, such as use of
-methods and inheritance, see the library code -- especially the window
-modules are full of them.)
+methods and inheritance, see the library code.)

Demo/classes/class.doc

-New features of classes
-=======================
-
-A class can implement certain operations that are invoked by special
-syntax (such as subscription or arithmetic operations) by defining
-methods with special names.
-
-
-Special methods for any type
-----------------------------
-
-__repr__(self) --> string
-
-Used by the print statement and conversions (reverse quotes) to
-compute the string representation of an object.
-
-__cmp__(self, other) --> int
-
-Used by all comparison operations.  Should return -1 if self<other, 0
-if self==other, +1 if self>other.  Due to limitations in the
-interpreter, exceptions raised by comparisons are ignored, and the
-objects will be considered equal in this case.
-
-
-Special methods for sequence and mapping types
-----------------------------------------------
-
-__len__(self) --> int
-
-Used by the built-in function len().  Should return the length of the
-object, which should be >= 0.  Also, an object whose __len__() method
-returns 0 
-
-__getitem__(self, key) --> value
-
-Used to implement value = self[key].  Note that the special
-interpretation of negative keys (if the class wishes to emulate a
-sequence type) is up to the __getitem__ method.
-
-__setitem__(self, key, value)
-
-Used to implement self[key] = value.  Same note as for __getitem__.
-
-__delitem__(self, key)
-
-Used to implement del self[key].  Same note as for __getitem__.
-
-
-Special methods for sequence types
-----------------------------------
-
-__getslice__(self, i, j) --> sequence
-
-Used to implement self[i:j].  Note that missing i or j are replaced by
-0 or len(self), respectively, and len(self) has been added to negative
-i or j.
-
-__setslice__(self, i, j, sequence)
-
-Used to implement self[i:j] = value.  Same note as for __getslice__.
-
-__delslice__(self, i, j)
-
-Used to implement del self[i:j].  Same note as for __getslice__.
-
-
-Special methods for numeric types
----------------------------------
-
-__add__, __sub__, __mul__, __div__, __mod__, __divmod__, __pow__,
-__lshift__, __rshift__, __and__, __xor__, __or__
-
-Used to implement the binary arithmetic operations (divmod and pow are
-called by built-in functions).  All have the call pattern
-func(self, other) --> number.
-
-__neg__, __pos__, __abs__, __invert__
-
-Used to implement the unary arithmetic operations (-, +, abs and ~).
-All have the call pattern func(self) --> number.
-
-__nonzero__(self) --> int
-
-Used to implement boolean testing.  An alternative name for this
-method is __len__.
-
-__coerce__(self, other) --> (self1, other1) or None
-
-Used to implement "mixed-mode" numeric arithmetic.  Either return a
-tuple containing self and other converted to some common type, or None
-if no way of conversion is known.  When the common type would be the
-type of other, it is sufficient to return None, since the interpreter
-will also ask the other object to attempt a coercion (but sometimes,
-if the implementation of the other type cannot be changed, it is
-useful to do the conversion to the other type here).
-
-__int__(self) --> int
-__long__(self) --> long
-__float__(self) --> float
-
-Used to implement the built-in functions int(), long() and float().
-
-
-Notes
------
-
-Except for __repr__ and __cmp__, when no appropriate method is
-defined, attempts to execute the operation raise an exception.  For
-__repr__ and __cmp__, the traditional interpretations are used
-in this case.