rebaseline.py: split image-based rebaselining, which will go away soon, into its own script

tools/tests/rebaseline/input/json1/base-macmini/expected-results.json

Index: tools/tests/rebaseline/input/json1/base-macmini/expected-results.json
===================================================================
--- tools/tests/rebaseline/input/json1/base-macmini/expected-results.json	(revision 0)
+++ tools/tests/rebaseline/input/json1/base-macmini/expected-results.json	(revision 0)
@@ -0,0 +1,26 @@
+{
+   "expected-results" : {
+      "aaclip_565.png" : {
+         "allowed-digests" : [
+            [ "bitmap-64bitMD5", 12345 ]
+         ],
+         "ignore-failure" : false
+      },
+      "aaclip_8888.png" : {
+         "allowed-digests" : [
+            [ "bitmap-64bitMD5", 67890 ]
+         ],
+         "ignore-failure" : false
+      },
+      "aaclip_gpu.png" : {
+         "allowed-digests" : [
+            [ "bitmap-64bitMD5", 11899819492385205974 ]
+         ],
+         "ignore-failure" : false
+      },
+      "aaclip_pdf.png" : {
+         "allowed-digests" : null,
+         "ignore-failure" : false
+      }
+   }
+}