Squashed commit of the following:

commit 9bea6afe8077a8e10ed5f013a49d916d75259d1c
Author: maciejlach <maciej.lach@gmail.com>
Date:   Thu May 22 15:59:39 2014 +0200

    test

commit 1810e4ef7224fe0b94d25d9c5d53425f84df8203
Author: maciejlach <maciej.lach@gmail.com>
Date:   Thu May 22 15:21:59 2014 +0200

    update guidelines

commit 1f94134880d3502c0e82d9b739c96e63b8acca88
Author: maciejlach <maciej.lach@gmail.com>
Date:   Thu May 22 15:18:38 2014 +0200

    add GUIDELINES.md