Changed indentation of ConnectFourGameGUI.java

Following Google drive to-do list, ConnecfFourGameGUI.java now doesn’t
exceed 5 levels of indentation.
Created a new method “createThread()’ this is accompanied with Doxygen
comment and as far as Eclipse reports, there are not build errors.

Checked the OthelloGameGUI/java too and it appears there to be 5 levels
indentation, but no more. Will check again in the morning when I’m more
awake.

Love Aaron x