Relaced all instances of "KID" with "TID" (Issue #21)

Replaced all references to "KID" (Key ID) in copied key module code with
"TID" (Training ID).
Replaced all instances of "key_" with "training_" (Issue #21)

Replaced all instances of "key_" with "trianing_" as I was reasonably
sure that none of these were a reference to an array key, or something,
instead.