add 'x' command to erase a character under the cursor

src/gui/BufferPane.cc

@@ -345,6 +345,17 @@ void BufferPane::handle_key(uint32_t keyval)
         case 'l':
             cursor_move(CursorMovement::RIGHT);
             break;
+        case 'x':
+            if (**m_iterator != '\n')
+            {
+                m_buffer->erase_code_point(*m_iterator);
+                if (**m_iterator == '\n')
+                {
+                    m_iterator->go_left_in_line();
+                }
+                m_window->request_redraw();
+            }
+            break;
         }
     }
 }