Set awt headless by default

[anna-shchurok]

Here is couple of concerns:

1. Setting headless property by default. On the one hand we let users to not write headless() each time they face the issue Could not initialize class sun.awt.X11GraphicsEnvironment, on the other - there are can be users which have AWT in their project and they don't need to be headless and they will be struggling to seek the cause. So here is the choice between having issue and write headless each time or having issue and seek of it and write headless(false). My opinion having property by default will be better for bigger amount of users.
2. Coding. The way it is done right now will require to write 2 lines like

Shutterbug.configure().headless(false);
Shutterbug.shootPage(driver).save();

Another way of implementing this is having Singleton of Shuttebug class and return the instance of it.
in this case it is possible to write like Shutterbug.headless(false).shootPage(driver);, but we will call static methods on instance, which is 😩 you know.