we know that packed data structures are not as efficient

this allows for secondary sensors

We now limit the target stopping point to 1x the xy leash length while
previously it was 2x.  This is justified because this limit is only used
when the copter is travelling at higher speeds but at higher speeds air
drag tends to make the copter stop more quickly naturally.

Without this initialisation the first RTL could be too aggressive as it
tries to stop too suddenly

The main rotor ramp was being held back by the rotor speed estimate
instead of being allowed to jump up to the estimate if it's lower.

Also fixed some incorrect indentation

Set FRAME parameter to 10

this enables the DATA96 packet to be sent