style: enforce spaces after keywords, add spaces

Moving the `requireSpaceAfterKeywords` rule to jscs with associated changes.

Is it preferred to explicitly specify the keywords in an array?

Or use `requireSpaceAfterKeywords = true`
which is equivalent to `requireSpaceAfterKeywords = [ 'do', 'for', 'if', 'else', 'switch', 'case', 'try', 'catch', 'void', 'while', 'with', 'return', 'typeof', 'function'];`

Although it doesn't make sense for `function`.

cc: @caitp
Although this kind of change would be hard to automate since it's hard to know if they original author was intending to use type coercion or not. And maybe they want to use `== null`?