Hi,

This patch adds a `space-before-keyword-exp` cleanup to CC Mode that 
inserts a space between a keyword and its subsequent opening 
parenthesis. For example, typing `if(` will clean up to `if (`. Clean up 
occurs when the opening parenthesis is typed, as per `space-before-funcall`.

I would appreciate any feedback. This is my first attempt to contribute; 
I'm not sure if this requires a copyright assignment.

Thanks,
Jason