[MSA] Open a directory where setup_assistant.launch was started. (mov…

…eit#509)

**Issue**
When editing an existing moveit_config pkg, MSA opens the location of MSA packace, which is useless.

**Approach with the suggested change**
Opens the "current" directory where `setup_assistant.launch` was started, which is often where the existing moveit_config package you'd like to edit is located.

moveit_setup_assistant/src/widgets/setup_assistant_widget.cpp

@@ -47,6 +47,7 @@
 #include <QPushButton>
 #include <QCloseEvent>
 #include <QMessageBox>
+#include <QString>
 #include <pluginlib/class_loader.h>  // for loading all avail kinematic planners
 // Rviz
 #include <rviz/render_panel.h>
@@ -106,6 +107,16 @@ SetupAssistantWidget::SetupAssistantWidget(QWidget* parent, boost::program_optio
     ssw_->stack_path_->setPath(args["config_pkg"].as<std::string>());
     ssw_->select_mode_->btn_exist_->click();
   }
+  else
+  {
+    // Open the directory where the MSA was started from.
+    // cf. http://stackoverflow.com/a/7413516/577001
+    QString pwdir("");
+    char* pwd;
+    pwd = getenv("PWD");
+    pwdir.append(pwd);
+    ssw_->stack_path_->setPath(pwdir);
+  }
 
   // Add Navigation Buttons (but do not load widgets yet except start screen)
   nav_name_list_ << "Start";