src: migrate pthreads to uv_threads

- So it can be compatible in every platform supported by libuv.
- Use attached threads instead of detached.
- Remove all CardReader 'status' listeners before emitting the
  'end' event.

lib/pcsclite.js

@@ -59,6 +59,11 @@ module.exports = function() {
                     r.state = state;
                 });
 
+                r.on('_end', function() {
+                    r.removeAllListeners('status');
+                    r.emit('end');
+                });
+
                 p.emit('reader', r);
             });
         });
@@ -102,7 +107,6 @@ CardReader.prototype.disconnect = function(disposition, cb) {
 };
 
 CardReader.prototype.transmit = function(data, res_len, protocol, cb) {
-
     if (!this.connected) {
         return cb(new Error("Card Reader not connected"));
     }