Add CIPD GAE SDK recipe module and packager.

scripts/slave/recipes/dart/packages.expected/pkg-mac10.11-release-be.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--spec",
       "cache_dir = '[GIT_CACHE]'\nsolutions = [{'deps_file': 'DEPS', 'managed': False, 'name': 'sdk', 'url': 'https://chromium.googlesource.com/external/github.com/dart-lang/sdk.git'}]",
       "--patch_root",
       "sdk",
@@ skipping 107 matching lines @@
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[build::zip]/resources/unzip.py"
     ],
     "name": "Unzip sdk",
-    "stdin": "{\"output\": \"[SLAVE_BUILD]/sdk/xcodebuild/ReleaseX64\", \"zip_file\": \"[SLAVE_BUILD]/sdk/sdk.zip\"}"
+    "stdin": "{\"output\": \"[SLAVE_BUILD]/sdk/xcodebuild/ReleaseX64\", \"quiet\": false, \"zip_file\": \"[SLAVE_BUILD]/sdk/sdk.zip\"}"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/sdk/tools/test.py",
       "--mode=release",
       "--arch=x64",
       "--use-sdk",
       "--compiler=none",
@@ skipping 81 matching lines @@
     ],
     "cwd": "[SLAVE_BUILD]/sdk",
     "name": "debug log"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]