Create .editorconfig

[Why?](http://editorconfig.org/#overview) This file can enforce file formatting in [IDE, text editors and others](http://editorconfig.org/#download) via plugin. It is KISS and kind to lazy developers (don't configure IDE for each project just install plugin and let project decide).

`indent_size` is not necessary anyone can set it to whatever he/she/it likes.

*I don't want to see crying notepad, pspad, emacs or vi users.*