With range(10000), doesn't fit into 128K heap.

Please don't submit patches with tab indentation!

Test function needs to be called by something else. Test heap size reduced so
its dump fits on a screenful of a typical terminal.

With a nice traceback, helps debugging much better.

Addresses issue #275.

Addresses issues #272 and #273.

Updated teensy to work with latest on master

Get rid of calloc().

Clean up handling of function return type annotation.

Added analogRead, analogWriteXxx and servo support for teensy.

If there's malloc and memset, then there's no need for calloc, especially if
we need to implement it ourselves.

Unlike CPython socket, microsocket object already implements stream protocol
(read/write methods), so makefile() just returns object itself. TODO: this
doesn't take care of arguments CPython's makefile() may accept.

Implementation is duplicated, but tolerate this for now, because there's
no clear idea how to de-dup it.

It's no longer intended to provide just "raw" socket interface, may include
some convenience methods for compatibility with CPython socket - but anyway
just minimal set required to deal with socket client and servers, not wider
network functionality.

Passing keyword arguments to a native function now no longer requires
heap memory.  The kw_args map is created on the stack using the args
array as the table.

This allows keyword maps to be created directly from stack data.

Can't decide which is better for string type, char or byte pointer.
Changing to char removes a few casts.  Really need to do proper unicode.

If SD card is present on (soft) reset then it's mounted on 1:/ and files
can be openned using, eg, open('1:/test.txt', 'r'), or 'w' for writing.

Linear table at the moment, to eventually be replaced with a hash table
generated by a preprocessor.

Dynamic table is retained so that builtins can be overridden.