linting/refactoring

* converts tabs to spaces
* removes trailing whitespaces
* removes unnecessary license file headers
* adds newline character at end of files
* brakes lines to 80 characters (if possible)
* adds/removes semicolons

With the help of `gjslint` and [google js styleguide](https://google-styleguide.googlecode.com/svn/trunk/javascriptguide.xml).