Changed RFrac equality in scripts

Now, fractions are considered equal if they have the same ratio:

- 6/6 == 12/12 => True
- 3/6 == 3/12  => False
- 1/6 == 2/12  => True

It's interesting to note this implementation is actually more
numerically stable than float comparison, though that wasn't really the
goal.

The main reason for this is to allow other fields to take over when
sorting multi-field fractional data: cov (lines + branches), testmarks
(passed + time), etc. Before, sorting would usually stop after
mismatched fraction fields, which wasn't all that useful.

scripts/cov.py

@@ -154,10 +154,18 @@ class RFrac(co.namedtuple('RFrac', 'a,b')):
     def __mul__(self, other):
         return self.__class__(self.a * other.a, self.b + other.b)
 
+    def __eq__(self, other):
+        self_a, self_b = self if self.b.x else (RInt(1), RInt(1))
+        other_a, other_b = other if other.b.x else (RInt(1), RInt(1))
+        return self_a * other_b == other_a * self_b
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
     def __lt__(self, other):
-        self_t = self.a.x/self.b.x if self.b.x else 1.0
-        other_t = other.a.x/other.b.x if other.b.x else 1.0
-        return (self_t, self.a.x) < (other_t, other.a.x)
+        self_a, self_b = self if self.b.x else (RInt(1), RInt(1))
+        other_a, other_b = other if other.b.x else (RInt(1), RInt(1))
+        return self_a * other_b < other_a * self_b
 
     def __gt__(self, other):
         return self.__class__.__lt__(other, self)