axTLS 2.1.3 brings support for TLS 1.2 and SNI. With MicroPython patchset
on top of it, the code size growth (x86) is ~2K.

ssl_client_new() accepts new SSL_EXTENSIONS* argument.

As enabled by SNI support in axTLS v2+.

The latest fashion is pushing certificate sub-chains, instead of a single
certificate, during TLS handshake. These are pushed via single TLS record
and effectively put minimum size limit on TLS record buffer. Recently,
these commonly grew over 4K, so we have little choice but to adjust.

The default for the GIL is to enable it if threading is enabled, and this
is the recommended way to use threading with the stmhal port.

These implementations are incorrect (eg f2d and d2f don't handle special
values like 0.0) and proper versions can be provided by libgcc (or
equivalent depending on the toolchain).

libgcc is now linked with the stmhal port so that library will provide
these functions from now on.

Following how extmod/modlwip.c does it.

In CPython 3.4 this raises a SyntaxError.  In CPython 3.5+ having a
positional after * is allowed but uPy has the wrong semantics and passes
the arguments in the incorrect order.  To prevent incorrect use of a
function going unnoticed it is important to raise the SyntaxError in uPy,
until the behaviour is fixed to follow CPython 3.5+.

This method follows the new HW API and allows to set a hard or soft IRQ
callback when a Pin has a level change.  It still remains to make this
method return a IRQ object.

It provides sys.stdin, sys.stdout, sys.stderr for bare-metal targets based
on mp_hal functions.

Also, add ipoll() documentation and markup changes to comply with CPython
usage.

In particular, require the real name and email address.

The CC3100 only allows to set a timeout for receiving data, not for accept,
connect or send.  But it can set non-blocking for all these operations and
this patch uses that feature to implement socket timeout in terms of non-
blocking behaviour combined with a loop.

This attempts to bootstrap network tests for MicroPython. This commits
sets test/net_inet/ as place for tests which require access to wide
Internet. They aren't intended to be run as part of the main testsuite,
instead to be run manually on demand.

test_tls_sites.py in particular check that it's possible to establish
SSL/TLS connection to select sites on the Internet: few references ones,
plus those for which problems were reported, and resolved.

Some of these tests don't require an Internet connection, but here is a
good place to put them for now.

This patch fixes a bug whereby the Python stack was not correctly reset if
there was a break/continue statement in the else black of an optimised
for-range loop.

For example, in the following code the "j" variable from the inner for loop
was not being popped off the Python stack:

    for i in range(4):
        for j in range(4):
            pass
        else:
            continue

This is now fixed with this patch.

Too big positive, or too big negative offset values could lead to overflow
and address space wraparound and thus access to unrelated areas of memory
(a security issue).

For SEEK_SET, offset should be treated as unsigned, to allow full-width
stream sizes (e.g. 32-bit instead of 31-bit). This is now fully documented
in stream.h. Also, seek symbolic constants are added.

Per POSIX, this is EINVAL, so raises OSError(EINVAL).

This allows the command to succeed without error even if there is no
$(BUILD)/build directory, which is the case for mpy-cross.

This prevents large files (eg larger than 2gb on a 32-bit arch) from
showing up as having a negative size.  Fixes issue #3227.

As per the "ESP8266 Technical Reference".

This macro is provided by stmhal/mphalport.h and makes sure the addr and
size arguments are correctly aligned.

…lopment) master.

cpx build compiles and loads and works in repl; test suite not run yet
esp8266 not tested yet