add option to show all search results in account lookup (bug 905689)

Allow searching for all user accounts, not just the top twenty sliced from ES results.

**When getting the maximum number of results, we know there are probably more results, show the Show All Results button**

![screen shot 2013-09-19 at 1 26 16 am](https://f.cloud.github.com/assets/674727/1171451/ea476340-2106-11e3-88ec-a6d35fbc1446.png)

**After clicking the Show All Results, we ask ES for all results and display in an overflow: auto list**

![screen shot 2013-09-19 at 1 26 48 am](https://f.cloud.github.com/assets/674727/1171457/faaedd9e-2106-11e3-859f-c0e610f58da0.png)