Please, fix accessibility issues in Ruby Gems dialog.

 No Accessible name :
   Class: javax.swing.JComboBox {  |  }
   Class: javax.swing.JTextField {  |  }

 No Accessible description :
   Class: javax.swing.JButton {  Browse |  }
   Class: javax.swing.JButton {  Manage... |  }
   Class: javax.swing.JComboBox {  |  }
   Class: javax.swing.JTabbedPane {  Gems Tabs |  }
   Class: javax.swing.JTextField {  |  }

 Components with no LABEL_FOR pointing to it :
   Class: javax.swing.JList {  Updated List |  N/A }
   Class: javax.swing.JTabbedPane {  Gems Tabs |  }
   Class: javax.swing.JTextField {  |  }
   Class: javax.swing.JTextPane {  Description |  N/A }