Merge pull request #30 from Akon32/multiverse

Small rework of action system
Define key mapping as a map.
Merge pull request #31 from codingteam/feature/key-refactor

Refactor key mapping
Fix knife damage, close #34.
Merge pull request #35 from codingteam/feature/knife-damage

Fix knife damage
Merge branch 'develop' into multiverse