Protocol more

[ginge]

app_timer: make more generic so other threads can use the service

protocol:

• qemu logic now no longer abuses memmove to parse the buffer. State engine tracks the header, only then adding to the main rx buffer
• rx is processed in the service thread in a loop until exhaused. Allows single payload multi packet handling
• service timer to allow a protocol endpoint to requst a transaction timeout

transfer:

• requests a timeout per section of the transfer.
• auto NACK on timeout of the transfer
• state machine to track states