As we dn't export constants for TCSANOW, etc., zero makes a good "don't
care" param, and now it will work also under Android Bionic and any other
libc.

The whole current port gets slurped into a static lib named
"libmicropython.a". Maybe that's not ideal, but at least something
to start with.

It makes much more sense to do constant folding in the parser while the
parse tree is being built.  This eliminates the need to create parse
nodes that will just be folded away.  The code is slightly simpler and a
bit smaller as well.

Constant folding now has a configuration option,
MICROPY_COMP_CONST_FOLDING, which is enabled by default.

Using 'P' format specifier (matches struct module). This is another shortcut
for FFI, just as previously introduced "array of objects" ('O').

Thanks to @nyov for the initial patch.

Use CTRL-E to enter paste mode.  Prompt starts with "===" and accepts
all characters verbatim, echoing them back.  Only control characters are
CTRL-C which cancels the input and returns to normal REPL, and CTRL-D
which ends the input and executes it.  The input is executed as though
it were a file.  The input is not added to the prompt history.

The usual cause would be that a cross-compiler for a port is not in PATH.

Apparently some cards need more than 2 retries.  See issue #1482.

This fix adds PIDs 9801 and 9802 to the pybcdc.inf file.

When in CDC only mode, it presents itself as a Communcations
device rather than as a composite device. Presenting as a
composite device with only the CDC interface seems to confuse
windows.

To test and make sure that the correct pybcdc.inf was being used,
I used USBDeview from http://www.nirsoft.net/utils/usb_devices_view.html
to uninstall any old pyboard drivers (Use Control-F and search
for pyboard). I found running USBDeview as administrator worked best.

Installing the driver in CDC+MSC mode first is recommended (since the
pybcdc.inf file in on the internal flash drive). Then when you switch
modes everything seems to work properly.

I used https://github.com/dhylands/upy-examples/blob/master/boot_switch.py
to easily switch the pyboard between the various USB modes for testing.

Not remove so far, may be needed later.

This patch eliminates the need for a nested parse node for assignments
and keyword arguments.  It saves a little bit of RAM when parsing.

In Python 3.4 the value is evaluated before the key.  In Python 3.5 it's
key then value.

Also adds tests specifically for testing constant folding.

Thanks to Peter Hinch.  Addresses issue #1488.

OpenJDK seemed to return NULL in case of exception, but Dalvik returns
arbitrary value, so skip such "optimizations".

Thanks to Peter Hinch.  See issue #1490.

* Move the esp.status() to network module.
* Describe the wifi.isconnected() method.
* Describe esp.mac(), esp.wifi_mode(), esp.phy_mode(), esp.sleep_type(),
  esp.deepsleep(), and esp.flash_id() functions.

From https://github.com/pfalcon/axtls , branch micropython.

All breaking changes going from 3.4 to 3.5 are contained in
basics/python34.py.