Make scores script more reliable

coffee/scores.coffee

 if table = document.querySelector '.match-editable'
-    inputs = table.getElementsByTagName 'input'
+    inputs = table.querySelectorAll 'input[type=number]'
     rows = table.children[1].children
     match_total = table.querySelector '.match-total'
     match_avg = table.querySelector '.match-avg'
 
-    w = table.querySelector('tbody tr').getElementsByTagName('input').length
+    w = table.querySelectorAll('tbody input[type=number]').length
     h = inputs.length / w
     scores = []
 
-    sub = (row) -> rows[row].children[w + 1]
-    tot = (row) -> rows[row].children[w + 2]
+    sub = (row) -> rows[row].querySelector '.row-total'
+    tot = (row) -> rows[row].querySelector '.total'
     num = (s) -> if s == '' or isNaN parseInt s then 0 else parseInt s
     timer = 0