hgrc.d: separate namespace for mercurial scripts 9diff and 9mail

hgrc.d: separate namespace for mercurial scripts 9diff and 9mail

--- a/contrib/plan9/hgrc.d/9diff.rc	Wed Aug 14 12:42:22 2013 -0500
+++ b/contrib/plan9/hgrc.d/9diff.rc	Thu Aug 15 21:35:56 2013 -0400
@@ -4,4 +4,4 @@
 extdiff =
 
 [extdiff]
-9diff = 9diff -cm $parent $child $root
+9diff = /bin/mercurial/9diff -cm $parent $child $root

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/contrib/plan9/hgrc.d/9mail.rc	Thu Aug 15 21:35:56 2013 -0400
@@ -0,0 +1,4 @@
+# The 9mail to support patchbomb and other email wrappers
+[email]
+method = /bin/mercurial/9mail
+