Updated shape to use style method

Hi again all!

This one involved a little more tweaking than the other ones. It looks like the configuration specs were using Shape (randomly?) so I had to update them to not look for a style hash since shape doesn't use it.

Tests pass and everything else was straight forward so I think this is ready to go. 

PS. I'll merge this (and others) after at least one reviewer gives me the go ahead as per (1) [here](https://github.com/shoes/shoes4/wiki/Merging-a-Pull-Request).
The spaceship operator affects all of ==, >, >=, <, <=, != (and I probably forgot some). It is a special operator. I think it is supposed to return -1 when self is smaller than the other object, 0 when they are equal and 1 when it is bigger than the other object. This way all of the operators mentioned above can be expressed in terms of the "spaceship operator". And in their default implementation actually all of them just use the space ship operator.