New Component: b:selectBooleanCheckbox

This pull requests adds a Bootstrap-enabled check box. It's used almost like the input field. The main difference is the caption, which is displayed behind the check box.

Example:

```HTML
<b:selectBooleanCheckbox label="label above the checkbox" 
                                            caption="click me!" 
                                            value="#{myBean.booleanAttribute}" />
```
Preview:
![image](https://cloud.githubusercontent.com/assets/3045767/4965128/799c01ae-677e-11e4-8538-a60192f716ac.png)