Save Blockrain activity context in Journal

[llaske]

The Blockrain activity don't store its current state and high score in the Journal. So when you close the activity everything is lost.

[llaske]

Blockrain activity source code is here: https://github.com/llaske/sugarizer/tree/dev/activities/Blockrain.activity
Adding datastore handling to an existing activity is explain here: https://github.com/llaske/sugarizer/blob/dev/docs/tutorial_step4.md

[llaske]

Fixed in 8f6a6f7.