Revert "Revert "Merge pull request +6235 from c9/mvh-redis-stats-performance""

This reverts commit a9eb23a4039719de8b4670e23d8b3d70015602d7.

Conflicts:
	package.json
	plugins/c9.api/project.js
	plugins/c9.docker/stats_collector.js
	plugins/c9.ide.performancestats/stats.js
	plugins/c9.sapi/docker_test.js

package.json

@@ -12,7 +12,7 @@
     "dependencies": {
         "acorn": ">=0.11.0",
         "amd-loader": "~0.0.5",
-        "async": "^0.9.0",
+        "async": "~0.2.7",
         "base64id": "~0.1.0",
         "c9": "0.1.0",
         "connect": "~2.12.0",