Describe that the only portable way to deal with addresses is by using
getaddrinfo(). Describe that some ports may support tuple addresses using
"socket" module (vs "usocket" of native MicroPython).
This clarifies return values and the handling of invalid (e.g. newline)
characters.
Encoding conforms to RFC 3548, but decoding does not, as it ignores invalid
characters in base64 input. Instead, it conforms to MIME handling of base64
(RFC 2045).
Note that CPython doesn't document handling of invalid characters in
a2b_base64() docs:
https://docs.python.org/3/library/binascii.html#binascii.a2b_base64 , so
we specify it more explicitly than it, based on CPython's actual behavior
(with which MicroPython now compliant).
The old intro talked about "differences", but there were hardly any
sections describing differences, mostly MicroPython specific features.
On the other hand, we now have real "differences" chapter, though it's
mostly concerned with stdlib differences.
So, try to avoid confusion by changing wording and linking to the other
chapters and contrasting them with what is described in "MicroPython
language".
Paul Sokolovsky
Alex Robbins
Javier Candeira
Alexander Steffen
Damien George