Basic matrix view for portfolio users

The styles for the population calculation results are embedded within <code>measure_calculation.less</code>.

If we move the following out (to somewhere like <code>mixins.less</code>; or embed the same styles within <code>matrix.less</code>) we can get styles on the popovers, too!
```
.pass {
  .text-success;
}
.fail {
  .text-danger;
}
.default {
  color: @brand-primary;
}
```

![screen shot 2014-08-15 at 10 14 54 am](https://cloud.githubusercontent.com/assets/456952/3934034/8e0625f6-2486-11e4-8ecf-83f8a1103fbf.png)