*WIP* Register Click

Hi all, I'm pushing this up while I'm still in a very early stage. I'm getting stuck on passing optional blocks via the ampersand `&block` syntax. 

I keep getting wrong number of argument errors and am now thoroughly lost :frowning:. I may just need a tutorial on passing and using option args . . . more comments in line.
At a glance, it looks like the problem is that there's no style hash. It's the call to `style[:stroke]` that fails, because `style` is `nil`.

You're right that `&blk` acts similarly to `blk = nil` (and you're also right that it doesn't act *exactly* like that :wink:)