honu-style operators

Work in progress at the moment but I wanted to get feedback on syntax. The honu syntax looks like:

```js
// binary_operator <name> <prec> <assoc> <binary transform>
// unary_operator <name> <prec>  <unary transform>
binary_operator raise 10 left {
  function (left, right) {
    syntax(pow(left, right))
  }
}
```

Some ideas using our syntax:

```js
binary_operator raise 10 left ($left, $right) {
    return #{Math.pow($left, $right)}
}
// $left and $right are implicit (or $lhs, $rhs) 
binary_operator raise 10 left {
    return #{Math.pow($left, $right)}
}
// could decide binary vs. unary by existence of assoc operator
operator raise 10 left {
    return #{Math.pow($left, $right)}
}
operator neg 10 {
    return #{-$op}
}
// using arrow
operator raise 10 left { $lhs, $rhs } => {
    return #{Math.pow($lhs, $rhs)}
}
// haskelly way (too terse IMO)
infixl 10 raise {
    return #{Math.pow($left, $right)}
}
left operator 10 {
    return #{Math.pow($left, $right)}
}
```

Any other ideas?