Merge pull request #65 from rising-thunder/cilop

Refactor socket order and fix sprite bugs
Deletes dead enemies from memory
Add xp and level attributes to player model
Add dmg attribute to player schema
Add xp dependency
Add xp field to enemy schema
Add leveling relationship
Adds message in chat when player kills enemy
Incorporate XP in server side logic
Incorporate login functionality
Saves user XP at logout
Awards XP on slaying monsters and records progress
Readies up player class for server side changes
Fix NaN XP bug when changing screens
Merge branch 'master' of https://github.com/rising-thunder/rasr