Documentation updates (mainly thru vs. through).

diff --git a/windows/multimon.c b/windows/multimon.c
index be4a2e7..e770482 100644
--- a/windows/multimon.c
+++ b/windows/multimon.c
@@ -155,7 +155,7 @@
 
                 break;
             }
-            /*fall thru */
+            /* fall through */
         case NULLREGION:
              return TRUE;
         case ERROR: