ribosome.js: pipe the stdout/stderr of the spawned process to that of…

… the ribosome process

adresses #59

ribosome.js

@@ -630,14 +630,17 @@ if (rnaopt) {
 }
 
 if (!rnaopt) {
-    exec("node " + rnafile + " " + process.argv.slice(3).join(' '),
-         function(error, stdout, stderr) {
-            process.stdout.write(stdout);
-            process.stderr.write(stderr);
-            fs.unlinkSync(rnafile);
-
-            if (error)
-                process.exit(error.code);
-         });
-}
+    var proc = exec("node " + rnafile + " " + process.argv.slice(3).join(' '));
+    proc.stdout.pipe(process.stdout);
+    proc.stderr.pipe(process.stderr);
+
+    proc.on('exit', function (code) {
+        fs.unlinkSync(rnafile);
+        process.exit(code);
+    });
 
+    proc.on('error', function (code) {
+        fs.unlinkSync(rnafile);
+        process.exit(code);
+    });
+}