more doc strings; limit jack reexport

src/jack.rs

@@ -4,7 +4,7 @@ use crate::core::*;
 
 submod!( device event factory ports );
 
-pub use ::_jack::{
+pub(crate) use ::_jack::{
     AsyncClient,
     AudioIn,
     AudioOut,
@@ -23,15 +23,14 @@ pub use ::_jack::{
     PortFlags,
     PortId,
     PortSpec,
-    ProcessHandler,
     ProcessScope,
     RawMidi,
     Transport,
     TransportState,
-    TransportStatePosition,
     Unowned
 };
 
+/// Wraps [Client] or [DynamicAsyncClient] in place.
 pub enum JackClient {
     Inactive(Client),
     Active(DynamicAsyncClient),