ogma-core: Fix comment in generated Copilot spec. Refs nasa#164.

The Copilot specification generated by Ogma includes the following
comment for the top-level `spec`:

```
-- | Complete specification. Calls the C function void handler(); when
-- the property is violated.
```

The comment is inaccurate, since the name of the function executed may
not be `handler`.

This commit fixes the comment to say that "handlers are executed when
properties are violated".

ogma-core/src/Language/Trans/Spec2Copilot.hs

@@ -197,9 +197,9 @@ spec2Copilot specName typeMaps exprTransform showExpr spec =
     -- Main specification
     copilotSpec :: [String]
     copilotSpec = [ ""
-                  , "-- | Complete specification. Calls the C function void "
-                    ++ " handler(); when"
-                  , "-- the property is violated."
+                  , "-- | Complete specification. Calls C handler functions"
+                    ++ " when"
+                  , "-- properties are violated."
                   , "spec :: Spec"
                   , "spec = do"
                   ]