Implements a very basic ai that moves towards the player.
Implements attacking on basicAi
Merge branch 'feature/basic-ai' into develop
Closes game on player death.
Mobs can move in straight lines.
Mobs don't step on each other.
Mobs don't attack each other if they are the same faction.
Mobs can have multiple factions. Also fixes heal on attack if defense is higher than atk.
Merge branch 'feature/factions' into develop

Implements a faction system, a mob won't attack (nor move towards) a mob that belongs to one of the same factions that he does.
Fixes attacking bug when going below 0 hp
Writes to log file, and reads out of it to write the game log.
Can now open a bigger log window to see older messages.
Ignore log.txt
Delete contents of log.txt on open, and create it if necessary.
Merge branch 'feature/text-log' into develop
Can pickup item from ground. Nothing to store it in yet.
Mobs convert to item(corpse) when they die.
Adds effect to item, able to use them. (Not yet handled by input)
Potions have their own potency.
Player can open usable inventory, and use an item.