Implement type virtual equality method support and implement comparisons for lists

Added memzip filesystem support for teensy

Add AssertionError.

Currently it would report "operation not supported" which is confusing. Overall,
this is thinko leading to undefined behavior.

You can now append a zipfile (containining uncomressed python sources)
to the micropython.hex file.

Use MEMZIP_DIR=directory when you call make, or set that in your
environment to include a different tree of source files.

Added sample /boot.py, /src/main.py, /test.py and /src/test.py files.

Added run command so that you can execute scripts from REPL (until import is implemented).

Added build directory to .gitignore

Still need to make built-ins by these names, and write tests.

Fixes Issue #132.

Merge RT_COMPARE_OPs with RT_BINARY_OPs.

compile_for_stmt_optimised_range(): Properly handle negative & unknown s...

Crude attempt to implement RAISE_VARARGS (with args=1 so far only).

list: Implement list multiplication.

Added dict.fromkeys.

If step is not constant, in first approximation, we can't apply optimization,
(well, we could, but need a special case for this).

Fix usart_obj_tx_str

* Fix usart_obj_tx_str to send the actual string.
* Fix issue #126

dict views now, refactoring later.