infrastructure: Express preference for published git repos

* HACKING: Express notion that a published git repository is
  preferred.  Fold request for commit message into patch section.
  Express desire for comments in code explaining correctness of
  post-commit state, and for commit message to explain correctness of
  the change.
diff --git a/HACKING b/HACKING
index 55c0343..0358fed 100644
--- a/HACKING
+++ b/HACKING
@@ -247,6 +247,14 @@
 installed together.
 
 
+GIT COMMIT SUBSMISSION
+
+The preferred method for changes is to provide git commits via a
+publically-accessible git repository.
+
+All content guidelines in PATCH SUBMISSION apply.
+
+
 PATCH SUBMISSION
 
 * Send a clean diff against the 'master' branch of the quagga.git
@@ -256,15 +264,17 @@
 
     git diff -up mybranch..remotes/quagga.net/master
 
-  Or by using git-format-patch.
+  It is preferable to use git format-patch, and even more preferred to
+  publish a git repostory.
 
-*  Not doing so is a definite hindrance to patch application.
+  If not using git format-patch, Include the commit message in the email.
+
+* After a commit, code should have comments explaining to the reviewer
+  why it is correct, without reference to history.  The commit message
+  should explain why the change is correct.
 
 * Include NEWS entries as appropriate.
 
-* Please, please include an appropriate commit message with any emailed
-  patches. Doing so makes it easier to review a patch, and apply it.
-
 * Include only one semantic change or group of changes per patch.
 
 * Do not make gratuitous changes to whitespace. See the w and b arguments