py: Make stream seek correctly check for ioctl fn; add seek for textio.
README: Update link to logo.
Set PYTHONIOENCODING='utf-8' so that unicode tests can pass on CPython on
systems where another encoding is set in the locale
py: Add support for float/double arrays in array module.

Addresses issue #981.
windows: Update config with latest features

- update mpconfigport.h to reflect latest unix version
- fix compilation error in modure due to msvc not allowing dynamic arrays
drivers, cc3000: Cleaning up, make local functions static.
moduhashlib: Initial module skeleton.
moduhashlib: Add sha256 implementation from "crypto-algorithms" project.

https://github.com/B-Con/crypto-algorithms revision 100f4ff
moduhashlib: Integrate sha256 implementation.
tests: Add test for hashlib.sha256 .
stmhal: Enable DAC on STM32F4DISC.

Addresses issue #987.
Adding CAN filter management