Schlib: add rounding to mm/mil conversion

The new kicad_sym format uses millimeters instead of mils. That required some
conversion in the check-scripts since symbols live on a 100mil grid.
Unfortunately floating-point math has some rounding issues which are addressed
in this commit.

Resolves: #349

schlib/kicad_sym.py

@@ -122,7 +122,7 @@ def as_json(self):
 
     def compare_pos(s, x, y):
         if 'posx' in s.__dict__ and 'posy' in s.__dict__:
-            return s.posx == x and s.posy == y
+            return round(s.posx, 6) == round(x, 6) and round(s.posy, 6) == round(y, 6)
         return False
 
     @classmethod

schlib/rules/rule.py

@@ -11,7 +11,7 @@
 from rulebase import *
 
 def mil_to_mm(mil):
-    return mil * 0.0254
+    return round(mil * 0.0254, 6)
 
 def mm_to_mil(mm):
     return round(mm / 0.0254)