There should be a way to automatically use ParameterBinding in sql and sqls interpolators

[kbrowder]

So currently if you have a custom binding (which you may want in order to use composite types for instance) it wont work in sql"" or sqls"" interpolators.

I think the way around this is do something like the following:

case class WithBinding(orig: Any, binding: ParameterBinder)
object WithBinding {
  implicit def toWithBinding[A: ParameterBinderFactory](a: A):WithBinding =
    WithBinding(a, implicitly[ParameterBinderFactory[A]].apply(a))
}

And add the following to the SQLInterpolationString class:

def bound_sql[A](params: WithBinding*) = 
  sql[A](params.map(_.binding):_*)

def bsql[A](params: WithBinding*) = bound_sql(params:_*)

def bound_sqls(params: WithBinding*) =
  sqls(params.map(_.binding):_*)

def bsqls(params: WithBinding*)= bound_sqls(params:_*)

Basically this adds new interpolators that only accept parameters that can be implicitly bound. Actually it may be the case that this is reasonable to just change sql/sqls interpolators however this would prevent passing anything in that's not bindable, perhaps that's a good thing, but it would prevent doing things like passing a PGobject directly which may be a bit extreme.