new feature

1. 「show current activity」can show any current activity name.
2. 「grid line」can show a grid line for debug UI.
3. 「setting」can config some value like shaking threshold and so on.

optimization

1. a new 「view hierarchy」for better display.
2. merge 「select」and 「position」, enhancing the ability to select views.
3. no need any code to init pandora.