Syntactic sugar for partials

[leMaik]

It would be cool if there was some more syntactic sugar for partial function definitions.

• (fn _ 42) should be equivalent to (partial fn (math/const 42) 1)
• (fn 42) (where fn is known to be a function with more than one parameter) should be equivalent to (partial fn (math/const 42) 0)
• The above should also work with non-lambda functions, i.e. (math/add 1) should be equivalent to (defco bindAdd [param] (partial (fn [x y] (+ x y)) param 0)) (bindAdd 1). Note that the optimizer will be able to remove these cases, so there would be no performance penality at all.