Add jscs rule for function spacing

Add rule disallowSpacesInFunctionDeclaration beforeOpeningRoundBrace.

```
function a() {

};
```

Add rule disallowSpacesInNamedFunctionExpression beforeOpeningRoundBrace.

```
var a = function a() {

}
```

Add rule requireSpacesInFunction beforeOpeningCurlyBrace. Applies to all types of functions.

Didn't include spacing for round brace for anonymous functions yet.
Checking only anonymous function expressions: for `function (e)`, got 1121 times.
Checking only anonymous function expressions: for `function(e)`, got 9159 times.

cc: @caitp @petebacondarwin
LGTM --- although I'd still like the `function ()` vs `function()` inconsistency fixed :< can wait for another CL.