Change raw "except:" constructs to pass on KeyboardInterrupt.

Bugfix candidate?  Don't know -- never bothered me, but it's minor
either way.
diff --git a/Lib/doctest.py b/Lib/doctest.py
index 2829f1e..db120a1 100644
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -430,6 +430,8 @@
                          compileflags, 1) in globs
             got = fakeout.get()
             state = OK
+        except KeyboardInterrupt:
+            raise
         except:
             # See whether the exception was expected.
             if want.find("Traceback (innermost last):\n") == 0 or \
@@ -521,6 +523,8 @@
         # just in case CT invents a doc object that has to be forced
         # to look like a string <0.9 wink>
         doc = str(doc)
+    except KeyboardInterrupt:
+        raise
     except:
         return 0, 0