Space before first arg

This is what I came up with for #856.

One lint cop for the possibly dangerous practise of putting the method name and first argument together. For example `func!x` -- does it mean `func!(x)` or `func(!x)`? It's the first one, but that might not be the author's intention. And there are other pitfalls.

Then there's a style cop for using too much space before the first argument. Actually, I found a lot of code in gems that have table alignment of method calls with arguments, so I'm not sure how many people will leave this cop enabled. Anyway, there it is.