Sample list improvements in Project View

This PR introduces several enhancements for the samples list in the project view (kind of a clone of what you can do in the project list):
* Possibility to search within the samples list:
![screen shot 2014-05-28 at 17 18 03](https://cloud.githubusercontent.com/assets/1574147/3106414/73601a7a-e67b-11e3-84c3-7198295c80b4.png)
* Sort sample list by column name (click on the header)
* Choose columns to display, and default presets:
![screen shot 2014-05-28 at 17 18 51](https://cloud.githubusercontent.com/assets/1574147/3106416/79b30784-e67b-11e3-9fb9-3a531b642e65.png)