Added beginnings of Coding-Style.md, fixed safe proposal based on latest discussion and fixed of adding a traversal tutorial with TRAVOpt and so on

tutorials/Coding-Style.md

+- The body of an if condition should at preferably have brackets. If the body has just one statement you may leave out the `{}` but in that case put the statement indented on another line. Also only do this if you think it unlikely that you will add more statements to the body later.