fix minor issues on description, formatting
rename professional javascript to high quality for better consistency

Internally the terms high quality and professional were used
interchangably. They all have been renamed to the consistent term
"high quality" which fits better to "low budget".
fine tune equpment description
tune damage probability

The lb wp has a high probablility to be damaged, due to it's low quality
state. The hq wp is very solid and withstands a certain amount of laser
fire.
whitespace
fix bug in initialization, determination of equipment present

Currently EquipmentInfo.infoForKey("EQ_XXX") had been used to determine,
if an equipment is present. This is wrong, it justs reveals, if the
equipment is known at all to Oolite. To find out whether it attached to
the ship, we have to use player.ship.equipmentStatus. This now has been
fixed for the initialization process.
remove obsolete local var
fix bug in playerBoughtEquipment event

Here we used the wrong method to determine present equipment as well.
Now the custom function _isEquipmentPresent() is used, instead of the
EquipmentInfo.infoForKey() function, wrongly used before.
increase wp sounds volume

When having background sounds the sounds were not noticable. They have been
increased to a decent volume.