Add training data to rate rules, and also do averaging of the tree!

Training data can now be visualized as the rate rules that they become.
In the short and long description this is differentiated from normal
rate rules with the additional comment "Rate rule generated
from training reaction."

Turns out that our kinetics were only displaying the top node kinetics
since the database was never averaging up. Now this is done so kinetics
search should be more closely matching java.  Also the very long
averaging comments are reintroduced to the RMG-Py rate rule kinetics
entries.  Averaged nodes are not displayed in the rate rules page.