Parameterize ideal function size

grow/defs/pythag.yaml

@@ -1,30 +1,25 @@
 global_memory_size: 2
 function_memory_size: 1
 instruction_limit: 20
+
+instructions_per_function_mean: 5
+instructions_per_function_std_dev: 3
+
 samples:
 - in:  [3,4]
   out: [5]
 
-- in:  [5,12]
-  out: [13]
-
-- in:  [8,15]
-  out: [17]
-
 - in:  [7,24]
   out: [25]
 
-- in:  [20,21]
-  out: [29]
-
-- in:  [12,35]
-  out: [37]
-
-- in:  [9, 40]
-  out: [41]
-
 - in:  [88, 105]
   out: [137]
 
+- in:  [140, 171]
+  out: [221]
+
+- in:  [105, 208]
+  out: [233]
+
 - in:  [161, 240]
   out: [289]