merge malloc+memset to calloc v2

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
remove duplicated check for no planets in player_land()

This check was already done a few lines above.

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
stop afterburn when autonav is braking for hyperjump

When trying to use a hyperjump point with autonav and afterburn,
I always miss the jump point and start moving in small circles.

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
add autonav button to mission screen

Having accepted a computer mission, I find myself frequently
opening the map just to enable autonav before taking off.

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
fix some typos in opengl comments

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
remove redundant include

All the opengl headers get included with opengl.h

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
fix merge