[TASK] Add editorconfig to provide basic settings in editor

Further explanation on http://editorconfig.org/
Note, that a plugin may be installed to use the editorconfig features. When using PhpStorm or an IntelliJ Idea use https://github.com/editorconfig/editorconfig-jetbrains#readme 
Sublime user need https://github.com/sindresorhus/editorconfig-sublime#readme and atom users may consider adding https://github.com/sindresorhus/atom-editorconfig#readme
This does only provide very, very basic settings.