For Bootstrap 3, you would need to use a custom wrapper and set its width to 100%.
.container-full {
margin: 0 auto;
width: 100%;
}
Here is a working example on Bootply
If you prefer not to add a custom class, you can acheive a very wide layout (not 100%) by wrapping everything inside a col-lg-12
(wide layout demo)
Update for Bootstrap 3.1
The container-fluid
class has returned in Bootstrap 3.1, so this can be used to create a full width layout (no additional CSS required)..