Port to ESP8266, add uhashlib, improved CAN driver. py core: - support more ops for bytes/bytarray - support __hash__ for user-defined types - support for float/double arrays in array module - shorter error messages for TERSE message option - add seek via ioctl to stream protocol extmod: - add uhashlib with sha256 unix port: - heapsize can take w specifier for word adjustment stmhal port: - CAN init now takes sjw, bs1, bs2 args - add CAN filter management - fix HAL error raising bug esp8266 port: - new port to ESP8266 wifi chip docs: - minor additions