Harvester capacity & unload time changed

The carrying capacity of harvesters was increased from $525 to $700. (This is the original C&C 95 value).
Overall harvesting rates are roughly the same.
To keep overall harvesting rates the same, the amount of time spent unloading at the refinery was increased. 
The purpose of these changes is to:
- make blue tiberium harvesting from distant fields economically feasible by increasing carrying capacity
- make basewalking less necessary in order to take advantage of blue tiberium fields farther away, especially in early game.
- make harvesting from distant tiberium fields less penalizing. If you have more harvesters harvesting tiberium farther away, the unload time won't affect you as much as if you were harvesting closer by.
- make refineries more relevant and make the player build refineries to increase capacity, and not only relying on a fleet of harvesters. (A good idea anyway since Ion cannons can kill refineries, and you should have more than one).
- keep with flavor of C&C, where tiberium was a dangerous substance which had to be carefully unloaded, unlike ore from RA which was immediately dumped.