One can instead lookup __name__ in the modules dict to get the value.

So now ticks_ms can count up to the full 30 bits.  Fixes issue #2412.

Instead of busy-looping waiting for UART input. Not enabled by default,
needs more testing.

A port now just needs to define FROZEN_DIR var and add $(BUILD)/frozen.c
to SRC_C to support frozen modules.

With FROZEN_MPY_DIR.

machine.POWER_ON is renamed to machine.PWRON_RESET to match other
reset-cause constants that all end in _RESET.  The cc3200 port keeps a
legacy definition of POWER_ON for backwards compatibility.

When dealing with a board which controls chip reset with UART's DTR/RTS,
we never see REASON_DEFAULT_RST (0), only REASON_EXT_SYS_RST (6). However,
trying a "raw" module with with just TXD/RXD UART connection, on power up
it has REASON_DEFAULT_RST as a reset reason.

According to the Arduino ESP8266 implementation the first argument to the
wifi scan callback is actually a bss_info pointer.  This patch fixes the
iteration over this data so the first 2 entries are no longer skipped.

Fixes issue #2372.

Interrupts during neopixel_write causes timing problems and therefore
wrong light patterns.  Switching off IRQs should help to keep the strict
timing schedule.

It's useful to be able to use symbolic links to add files and directories
to the set of scripts to be frozen.

This new config option allows to control whether MicroPython uses its own
internal printf or not (if not, an external one should be linked in).
Accompanying this new option is the inclusion of lib/utils/printf.c in the
core list of source files, so that ports no longer need to include it
themselves.

modpybhspi now does the needed multiplexing, calling out to modpybspi
(bitbanging SPI) for suitable peripheral ID's. modmachinespi (previous
multiplexer class) thus not needed and removed.

modpybhspi also updated to following standard SPI peripheral naming:
SPI0 is used for FlashROM and thus not supported so far. SPI1 is available
for users, and thus needs to be instantiated as:

spi = machine.SPI(1, ...)

There functionality is available via standard SPI class.

Both tested to work. (WDT_RESET can be seen by issuing machine.disable_irq()
and waiting for WDT reset, SOFT_RESET - by machine.reset()).

This extra forward slash for the starting-point directory is unnecessary
and leads to additional slashes on Max OS X which mean that the frozen
files cannot be imported.

Fixes #2374.

This allows 1-wire drivers (eg DS18X20) to perform in-place operations and
hence do less memory allocations.

The OneWire class is now in its own onewire.py module, and the temperature
sensor class is in its own ds18x20.py module.  The latter is renamed to
DS18X20 to reflect the fact that it will support both the "S" and "B"
variants of the device.

These files are moved to the modules/ subdirectory to take advantage of
frozen bytecode.

This is an object-oriented approach, where uos is only a proxy for the
methods on the vfs object.  Some internals had to be exposed (the STATIC
keyword removed) for this to work.

Fixes #2338.

Without this, spi.read(1, 0xff) would use 16 clock cycles,
first to send 0xff and then to receive one byte, as visible
with a logic analyzer.

Disabling it was an omission from early development stages.

This module uses ESP8266's SPI hardware, which allows much higher
speeds. It uses a library from
https://github.com/MetalPhreak/ESP8266_SPI_Driver

This type was used only for the typedef of mp_obj_t, which is now defined
by the object representation.  So we can now remove this unused typedef,
to simplify the mpconfigport.h file.

Pin(16) now works as an input.

To accommodate growing firmware.

Of them, 0x87000 is irom0 segment.

This is required to ship increasing number of modules and examples
developed in teh course of ESP8266 port project.