Commit 15 - Summary tab started, Model improved

Added two buttons which print summary stats (incomplete) to the
terminal. Users can now also just type in all the summoner/champ
combos and click "Get All" or "Get Summary" (i.e. no need to click
"Go" for every champ). Temporary changes to rankeddata.py
(dictionary key names), and one permanent (division by zero for KDA
 calculation). Small changes to GUI (everything is smaller for
 now). Cleaned up the model. Big change: now does a "snapshot
 check" in order to only generate stats for the current names in
 the GUI.