iloc errors when end is greater than length
IMO this should work

```
x = pd.DataFrame(np.random.rand(5,3))
x.iloc[:6]
```

Consider 

```
np.arange(5)[:7]
```

And 

```
range(5)[:7]
```

I'm on

```
[~/]
[14]: pd.version.version
[14]: '0.13.1-63-gcc6ee40'
```
