allow 'D' for @ALL repos

...so that the new semantics can be made system-default if someone wants
to do that

doc/3-faq-tips-etc.mkd

@@ -387,6 +387,19 @@ This provides the *greatest* backward compatibility (if you don't specify any
 `D` permissions, everything works just as before), while also enabling the new
 semantics at the granularity of a repo, instead of the entire config.
 
+Note 1: if you find that `RW+` no longer allows deletion but you can't see a
+`D` permission in the rules, remember that gitolite allows a repo config to be
+specified in multiple places for convenience, included delegated or included
+files.  Be sure to search everywhere :)
+
+Note 2: a quick way to make this the default for *all* your repos is:
+
+    repo @all
+        D   dummy-branch    =   foo
+
+where foo can be either the administrator, or if you can ignore the warning
+message when you push, a non-existant user.
+
 [sdrr]: http://groups.google.com/group/gitolite/browse_thread/thread/9f2b4358ce406d4c#
 
 #### file/dir NAME based restrictions

hooks/common/update

@@ -77,7 +77,7 @@ $perm = '+' if $oldsha ne $merge_base;
 
 # were any 'D' perms specified?  If they were, it means we have to separate
 # deletes from rewinds, so if the new sha is all 0's, change the '+' to a 'D'
-$perm = 'D' if $repos{$ENV{GL_REPO}}{DELETE_IS_D} and $newsha eq '0' x 40;
+$perm = 'D' if ( $repos{$ENV{GL_REPO}}{DELETE_IS_D} or $repos{'@all'}{DELETE_IS_D} ) and $newsha eq '0' x 40;
 
 my @allowed_refs;
 # @all repos: see comments in similar code in check_access