URBNG-142 - [WP] provide changing of TaskView according to task state (accomplished/active etc.)
URBNG-142 - [WP] changed tasks are marked on the list until user opens it for the first time after the change
URBNG-142 - [WP] Mark changes in task as provided in UX spec

Also:
* GameDetailsView - fixed icons, colors etc.
* removed dummy tests
* fixed comparing dates by GameChangesManager
Merge pull request #161 from Maxikq/windows_phone

URBNG-142 - [WP] provide changing of TaskView according to task state (accomplished/active etc.)