Rework pitch detection: To improve separation between pos and neg moves the history memory is now evaluated starting from the last detected start condition. This was needed because a small "overshoot" of the end position causes e.g. a pos event to be detected as negative event.

checksum_final_add_fletcher.exe OSTC4_firmware_upload.bin OSTC4_FONT_upload.bin OSTC4_RTE_upload.bin