Various cleanups reported by people using the alpha release.

Incorporate "order-only" prerequisites patch.  Wrote a test for it.
The test shows what might be a bug in the code; I need to look at it
more closely (anyway it doesn't behave as I expected).  Also I haven't
done the docs yet.

1 files changed, 2 insertions, 1 deletions

diff --git a/dep.h b/dep.h
index e6499219..7f4380b7 100644
--- a/dep.h
+++ b/dep.h
@@ -38,7 +38,8 @@ struct dep
     struct dep *next;
     char *name;
     struct file *file;
-    int changed;
+    unsigned int changed : 8;
+    unsigned int ignore_mtime : 1;
   };