Strict frame start check -> frame.py

[SaxonWood]

new option in frame.py -> ReceiveFrame Class -> consume

Class and consume function is backward compatible. Only if new parameter "strict_start_check" is set to True, the start of frame search will be stricter as before and expect a '00' preamble before the start-token. This helps to avoid the "invalid command" errors seen with newer inverter software versions.