…press builds.

…C made it slightly larger.

Enable ure, center, partition, frozenset, splitlines, reversed for Express builds.

Renamed spi flash to ext flash not to confuse with the actual spi flash

…ary.

…e build. Put it next to readline instead.

…age() not to be inlined even with -flto

Fix broken mp_stack_check() when using -flto

…duino's PID.

…but add more detail to the design guide about their use.

Fixes #148. Fixes #151

Also, change the MICROPY_ERROR_REPORTING checks to macros to make it
clear the compiler can handle it immediately.

Fixes #154

rather than 24bit. Setting the period for more than a 16bit number
caused the TCC to be in a weird state where resetting it would hard
crash.

Fixes #153

This fixes spurious "All timers in use" exceptions. Thanks to
@ladyada for finding this issue.

This fixes a hard lock that happens when using a second channel on an
in use TCC. The lock occurred when setting the duty cycle on the channel
because the hw address was not available to ASF.

Thanks to @ladyada for finding the bug.

Previously it was configured as four and four which configured
the incorrect channels.

A previous fix improved the duty_cycle channel value computation by
removing the reliance on the PER register which gave old values. It
saved the period on the object but failed to set anything for reused
timers. So, this breaks it out into a separate array that can be
shared across all object regardless of whether it used a new or
existing timer.

…talio.

Also, rename Direction.IN to Direction.INPUT and Direction.OUT to Direction.OUTPUT.

This simplifies using them. Prior to the nativeio split this would have led to
clutter in the top-level namespace but having digitalio prevents this.

Fixes #152

board specific functionality.

Fixes #155

Express to ensure the Neopixels are off after reloads.