Save button on app settings now btn-save

Some save buttons where `btn-primary` where throughout the application these usually are `btn-save`.

Before (Application settings)

![Screenshot_from_2016-01-26_09-44-32](/uploads/f4019349c8bac6e0c91e23252a70d334/Screenshot_from_2016-01-26_09-44-32.png)

After

![Screenshot_from_2016-01-26_09-45-20](/uploads/8e59a2b180832f44e3908b22187549af/Screenshot_from_2016-01-26_09-45-20.png)


See merge request !2612