[Grace-core] Layout rules for Grace

[James Noble]

> Gee, I like speed: aNumber.

:-)

which. following Scala, is probably where we end up.

http://docs.scala-lang.org/style

> Do we really need to set layout rules at this level of detail?  Why don't we just worry about indenting and not spacing or we'll drive everyone crazy.

We will, eventually, but not necessarily now. 
Once we get to building a formatter, then that would be the spec of the formatter..

James