Added Accuracy Factor

Player Ship has Accuracy factor for making it less accurate
Accuracy represents the speed of variation of the weapon while Max
Offset represents the largest distance from center the weapon can go.
Setting a lower accuracy can make the weapon appear to "burst" like a
shotgun instead of being less accurate with a sufficiently fast bullet
stream. Good values are:

Accuracy=0.98
Max=10
to make gun look mildly inaccurate.