Revise GetTransmitterScore to rate transmitters in joules per byte

[toadicus]

Currently, KSP rates the "best" transmitter to use when clicking "Transmit Data" on a science part with a GetTransmitterScore method in a couple of the Science classes. However, the metric doesn't make a lot of sense from a unit examination perspective, and weighs data capacity twice.

The stock implementation of GetTransmitterScore is:

Score = (1 + DataResourceCost) / DataRate

Lowest score wins.

The stock DataRate and DataResourceCost are:

DataRate = packetSize / packetInterval
DataResourceCost = packetResourceCost / packetSize

So:

Score = ((1 + packetCost)*packetInterval)/packetSize^2

The resulting score is essentially in terms of joules per byte per baud. Rearranging that a bit, it could also look like joule-seconds per byte per byte, or newton-meter-seconds per byte per byte. Either way, that metric doesn't seem like a very reasonable one.

Two metrics that might make more sense are joules per byte or watts per baud. Because KSP tightly couples power and bandwidth, they actually come out exactly the same at this point:

WattsPerBaud = (packetResourceCost / packetInterval) / (packetSize / packetInterval)
JoulesPerByte = packetResourceCost / packetSize