Reuse ItemManager constructed in GameStateLoad for GameStatePlay

Fixes #967
Merge pull request #1174 from dorkster/fixes

Reuse ItemManager constructed in GameStateLoad for GameStatePlay
Reset disabled icon overlay clip in actionbar when iterating

Fixes #1180
Prevent item activation on action bar when going from 0 -> 1 quantity

Fixes #1179
Merge pull request #1182 from dorkster/fixes

Reset disabled icon overlay clip in actionbar when iterating
Use get_random_neighbor for map loot
Add another int to Event_Component to better handle loot

This means less conversions from string to int when dropping loot.