Ability to restart selected subtasks from GUI. Pixel preview & subtask list preview. Subtask states

[jamuszyn]

*Task list with subtask details flow:
https://invis.io/ECJHKMEWF4Y#/299124045_Task-List-Pixel-Preview

*Select multiple subtasks:
https://invis.io/8PJHKO8FXT9#/299129306_Task-List-Subtask-Preview_02

*Subtask states:
https://invis.io/PVJHKQM3XK4#/299129521_Task-List-Subtask-Details-Computing

[Muhammed Tanrıkulu]

Related #321.