Points Breakdown
--------------------------------------------------------------
3 in a row:    10
4 in a row:    30
5 in a row:    80

additional 3 in a row:  x2
additional 4 in a row:  x3
additional 5 in a row:  x4
(So 4 + 3 would give you 30*2 = 60 points; 4 + 4 + 3 would
give you 30*3*2 = 180 points.)

Chains:
At each stage, add the point adjustment to the total for the 
chain, then double the chain total.  (So 3->4->3 would give
you 10->100->220 points; 4+3->3+3->3->3 would give you 
60->160->340->700 points (but each stage is added together,
so it's actually larger).