test-rebase: exhibit revisions which should have been skipped

This will be fixed in the next commit.

v2:
- Display emptied grafted revisions
- Use --git flag

tests/test-graft.t

@@ -227,6 +227,14 b' View graph:'
   |/
   o  [e-mail]: 0
   
+  $ hg export --git 8
+  # HG changeset patch
+  # User bar
+  # Date 0 0
+  # Node ID 6f5ea6ac8b705521c6d5f49a04ed142e3f76645d
+  # Parent  d2e44c99fd3f31c176ea4efb9eca9f6306c81756
+  1
+  
 Graft again onto another branch should preserve the original source
   $ hg up -q 0
   $ echo 'g'>g

tests/test-rebase-detach.t

@@ -398,4 +398,11 b' Ensure --continue restores a correct sta'
   |/
   o  0:draft 'A'
   
-
+  $ hg export --git 8
+  # HG changeset patch
+  # User test
+  # Date 0 0
+  # Node ID 248209b40064fe67181915fa7a4f3395520f700a
+  # Parent  02de42196ebee42ef284b6780a87cdc96e8eaab6
+  H2
+  

tests/test-rebase-mq-skip.t

@@ -137,3 +137,11 b' already has one local mq patch'
   |
   o  0: 'r0' tags:
   
+  $ hg export --git 4.diff
+  # HG changeset patch
+  # User test
+  # Date 0 0
+  # Node ID 315eb21a13c2b06e787f5d0000e36f8f8f3a1768
+  # Parent  1660ab13ce9aea3da22ea54926bd49aeff8a4e20
+  r4
+