Fix dropdown arrow for pull-right.


Problem description
===================

There is no option to set dropdown menu to pull right.


Changes description
===================

Added a configuration option to set pullRight.

Update CSS to place dropdown arrow on the right when pull-right is defined.

Before

![after](https://f.cloud.github.com/assets/204609/1033283/22952356-0ef9-11e3-8638-274e2c070003.png)

After
![before](https://f.cloud.github.com/assets/204609/1033282/1f299f58-0ef9-11e3-9f44-71c4d08c7909.png)

I have added tests for the new pullRight option.

I saw there is no test for 'appendWidgetTo' configuration option, so I tried to add it... but I failed.


Todo
-------

* [ ] Add documentation for new feature. To bad the documentation is not included in the main branch, together with code.

* [ ] Fix test for appendWidgetTo


How to try and test the changes
===============================

Create a time picker with `pullRight: true` option and check that it is right aligned and has the arrow on the right side.

Please check the test for appendWidgetTo and let me know what I did wrong and why the test is not passing.
It looks like it ignores the appendWidgetTo and appends to `.bootstrap-timepicker`

I can remove the test for appendWidgetTo and have this branch pass full test, but I prefer to have it written.

Thanks