new name for id (now ider) interface

more in line with go naming scheme for interfaces
better greppability
diff --git a/conn.go b/conn.go
index 3e682cb..e3e5309 100644
--- a/conn.go
+++ b/conn.go
@@ -126,6 +126,6 @@
 	conn
 }
 
-func (s *serverConn) sendError(p id, err error) error {
+func (s *serverConn) sendError(p ider, err error) error {
 	return s.sendPacket(statusFromError(p, err))
 }
diff --git a/server.go b/server.go
index 80edb09..3f21001 100644
--- a/server.go
+++ b/server.go
@@ -321,7 +321,7 @@
 	return err // error from recvPacket
 }
 
-type id interface {
+type ider interface {
 	id() uint32
 }
 
@@ -516,7 +516,7 @@
 	return ssh_FX_FAILURE
 }
 
-func statusFromError(p id, err error) sshFxpStatusPacket {
+func statusFromError(p ider, err error) sshFxpStatusPacket {
 	ret := sshFxpStatusPacket{
 		ID: p.id(),
 		StatusError: StatusError{