Plane: fixed Log when disarmed value in docs
AP_AHRS: removed empty file
AP_NavEKF: remove sleep on init of EKF

this prevents HIL from locking up, and also prevents a possible 1s
delay in flight on EKF init
DataFlash: fixed logging on PX4v1

large writes break IO, a NuttX bug
Git: ignore LASTLOG.TXT