Performance tweaks: 1) Removed extraneous list fetching for detect_straight and len() calling 2) Simplified get_high_cards to just return the top 5 cards in histogram,    without creating a new tuple or making a list comprehension.
Performance tweaks:
1) Removed extraneous list fetching for detect_straight and len() calling
2) Simplified get_high_cards to just return the top 5 cards in histogram,
   without creating a new tuple or making a list comprehension.

ktseng/holdem_calc,masaka9/holdem_calc