The while-loop that calls chop_component will guarantee that level==-1 at
the end of the loop.  Hence the code following it is unnecessary.

The check for p==this_name will catch imports that are beyond the
top-level, and also covers the case of new_mod_q==MP_QSTR_ (equivalent to
new_mod_l==0) so that check is removed.

There is also a new check at the start for level>=0 to guard against
__import__ being called with bad level values.

py/builtin.h declares mp_builtin_open with the first argument of type
size_t.  Make all implementations conform to this declaration.

Previously, only "selected chapters" were shown in left-pane ToC (of
Read The Docs theme). These chapters were selected out of order. The
rest of chapters were hidden beyond "Documentation Contents" pseudo-
chapter. This arguably led only to confusion, as many people probably
never tried to open that pseudo-chapter, and those who did, were
confused. Such organization is even worse for PDF output, causing
chapters go in mix-mashed order.

So, instead move to single clean ToC. This will allow readers of HTML
to have access to any doc content at their fingertips (and straight
before their eyes), and will allow to finally have clean PDF docs.

A previous version of the 1-wire driver (which was recently replaced by the
current one) had this behaviour and it allows to create a 1-wire bus
without any external pull-up resistors.

And and FLASH_FS, and use "K" values instead of hex numbers for lengths.

The increase of FLASH_TEXT is to allow more frozen bytecode for a
particular user's project.  It's not used for anything else.

The floating-point precision of the target is detected (0, 30, 32 or 64)
and only those tests which can run on the target will be run.

Move hardware-specific optimizations to the very end of document, and
add visible note that it gives an example for Pyboard. Remove references
to specific hardware technologies, so the doc can be more naturally
used across ports. Various markup updates to adhere to the latest
docs conventions.

Per the latest docs conventions.

This causes `symbol` syntax to be equivalent to :any:`symbol`, which is
in turn the easiest way to cross-reference an arbitrary symbol in the
docs:

http://www.sphinx-doc.org/en/stable/markup/inline.html#role-any

:any: requires at least Sphinx 1.3 (for reference, Ubuntu 16.03 ships
with 1.3.6, the latest 1.6.3).

Any many of our docs, `symbol` is misused to specify arguments to
functions, etc. Refactoring that is in progress. (CODECONVENTIONS
already specify proper syntax for both arguments and xrefs, based
on CPython conventions).

Based on what CPython uses. However, Read The Docs theme styles this
markup in very stand-out way, so we may think what to do about it.

If for nothing else, then at least to cross-reference them.

n_args is now actually used in this function.

Instead of default 2. 3 are required to access description of individual
library modules.

At least, Sphinx 1.3.6.

This follows similar warnings in other parts of docs.

In the future, a special runner for such tests will import each test and
call test() function with an address of test server to use.

The idea is that these tests can be run with just a test server running
on a test host, with device under test connecting to it, instead of
requiring Internet connection for testing.

Such setup is however WIP, and some tests in net_hosted/ are so far
written to connect to Internet, as there're not test server written
yet. This is expected to evolve over time.

GC finalization should be enabled for modlwip, or it may lead to GC
problems with socket objects. This decreases usable heap size from
36288 to 35968 (-320) bytes.

It belongs with the other pin config functions in machine_pin.c.  Also,
esp_mphal.c is put in iRAM so this change saves about 300 bytes of iRAM
(and mp_hal_pin_open_drain is not a time critical function so doesn't
need to be in iRAM).