Enforce bracket styles (Part 2)

- [x] setters

``` swift
set {
    oldValue = newValue / 2
}
```
- [x] getters

``` swift
get {
    return value * 2
}
```
- [x] extensions

``` swift
extension someExtension {
}
```
- [x] protocols

``` swift
protocol someProtocol {
}
```
- [x] enums

``` swift
enum someEnum {
}
```
- [x] closure

``` swift
func someFunction () -> () {
// closure
}
```
