Added skeletons of new files for the konstant attack and skill
Added konstant property of not rerolling
Removed konstant attack files --- instead, change BMAttackSkill
Added konstant property of not being able to power attack
Disabled single-die skill attacks by konstant dice
Merge remote-tracking branch 'upstream/master' into 259_konstant

Manually resolved conflict:
	src/engine/BMSkill.php
Added possibility for a konstant die to contribute negative value to skill attack
Fixed failing unit test
Made konstant dice unable to perform power attacks
Added in-game unit tests for konstant
Remove single-die skill attacks by konstant dice from the hit table
Fixed konstant logic to use BMDie->doesReroll instead of setting BMDie->max and BMDie->min to BMDie->value
Added unit tests to cover konstant skill hit targets
Refactored hit table code to do with single-die konstant skill attacks, so that it is now run by a die hook to BMSkillKonstant
Merge pull request #299 from blackshadowshade/259_konstant

Implemented the konstant skill