Script is equivalent, but now also runs under ancient Python 2.6.
Goes part way to addressing issue #847.

Code-info size, block name, source name, n_state and n_exc_stack now use
variable length encoded uints.  This saves 7-9 bytes per bytecode
function for most functions.

And move the MAP_ANON redefinition from py/asmx64.c to unix/alloc.c.

If not set, MICROPY_EMIT_X64 is set only if on x86-64 machine.

If not set, MICROPY_GCREGS_SETJMP is set when on MIPS.

Add allocation macros (per platform) and ARM cache flush

Fixes issue #840

Declare do_str() function before the implementation

This ensures that GCC does not discard the do_str implementation in
some cases eg when compiling tests with debug enabled:
  make RUN_TESTS=1 DEBUG=1

Allows to create socket objects that support TCP and UDP in server and
client mode.  Interface is very close to standard Python socket class,
except bind and accept do not work the same (due to hardware not
supporting them in the usual way).

Not compiled by default.  To compile this module, use:
make MICROPY_PY_WIZNET5K=1

Update teensy README.md file

Thanks to Artur Wroblewski for some suggested changes.
I also added the TIPs section at the end while I was updating.

Part of code cleanup, working towards resolving issue #50.

Part of code cleanup, working towards resolving issue #50.

Part of code cleanup, working towards resolving issue #50.

Part of code cleanup, to resolve issue #50.

Part of code cleanup, towards resolving issue #50.

Addressing issue #50, still some way to go yet.

Top-level lib directory is for standard C libraries that we want to
provide our own versions of (for efficiency and stand-alone reasons).
It currently has libm in it for math functions.

Also add atanf and atan2f, which addresses issue #837.

Found this bug by running unix/ tests with DEBUG=1 enabled when
compiling.

Addresses issue #838.

Optimises:
    if () -> if False
    if (x,...) -> if True
    if (a and b) -> if a and b

This way, the native glue code is only compiled if native code is
enabled (which makes complete sense; thanks to Paul Sokolovsky for
the idea).

Should fix issue #834.