* wip: add task scoring and persist checklist items
* remove unused files, fix checklist scoring and start adding support for groups tasks
* amke group and challenge tasks not scoreable
* Moved critical hit calculation from _addPoints() to _calculateDelta(). Added user as an input argument to _calculateDelta() so for critical hit calculation
* Changed test to expect task value of 1.5 after critical hit
* Revert "Moved critical hit calculation from _addPoints() to _calculateDelta(). Added user as an input argument to _calculateDelta() so for critical hit calculation"
This reverts commit 51b8ab6498.
* Moved critical hit calculation to _changeTaskValue(). Use value stored in user._tmp.crit in _addPoints()
* Test is no longer affected by critical hits
* Removed unneeded comment
* Added WIP test of critical hits
* Want the crit function to return 2 to test critical hits
* Changed crit function to export as a function within an object so that it can be stubbed for testing. References to the crit() function were updated to call crit.crit() instead
* Added test for increased experience on critical hits
