Minor:
* 0/1 for boolean values replaced with False/True.
* (887279) Added handling of POLLPRI as POLLIN.
POLLERR, POLLHUP,
POLLNVAL are handled as exception event.
handle_expt_event gets recent
error from self.socket object and raises socket.error.
* Default readable()/writable() returns False.
* Added "map" parameter for file_dispatcher.
* file_wrapper: removed "return" in close(), recv/read
and send/write
swapped because of their nature.
* mac code for writable() removed. Manual for accept()
on mac is similar
to the one on linux.
* Repeating exception changed from "raise socket.error,
why" to raise.
* Added connected/accepting/addr reset on close().
Initialization of
variables moved to __init__.
* close_all() now calls close for dispatcher object,
EBADF treated
as already closed socket/file.
* Added channel id to "unhandled..." messages.

Bugs:
* Fixed bug (654766,889153): client never gets
connected, nor errored.
Connecting client gets writable event from select(),
however, some client may want always be non writable.
Such client may
never get connected. The fix adds _readable() - always
True for
accepting and always False for connecting socket; and
_writable() -
always False for accepting and always True for
connecting socket.
This implies, that listening dispatcher's readable()
and writable()
will never be called. ("man accept" and "man connect"
for non-blocking
sockets).
* Fixed bug: error handling after accept().
It's said, that accept can return EWOULDBLOCK even for
readable socket.
This mean, that even after handle_accept(),
dispatcher's accept() still
raise EWOULDBLOCK. New code does accept() itself and
stores accepted
socket in self.__pending_accept. If there was
socket.error, it's treated
as EWOULDBLOCK. dispatcher's accept returns
self.__pending_accept and
resets it to None.

Features:
* Added pending_read() and pending_write(). The
functions helps to use
dispatcher over non socket objects with buffering
capabilities. In original
dispatcher, if socket makes buffered read and some data
is in buffer, entering
asyncore.poll() doesn't finishes, since there is no
data in real file/socket.
This feature allow to use SSL socket, since the socket
reads data by 16k chunks.