Update cljs, om, async versions

```
cljs           0.0-2322               -> 0.0-2511
core.async     0.1.267.0-0d7780-alpha -> 0.1.346.0-17112a-alpha
om             0.8.0-alpha2           -> 0.8.0-rc1
lein-cljsbuild 1.0.4-SNAPSHOT         -> 1.0.4
```