Update 1.3.1

Just a quick patch to fix a severe bug in level 11, and a few more things I got done. Here's the changelog:

Levels:

• Restored missing jail cell floor in level 2.
• Moved grenades pickup outside some barrels in level 3 secret.
• Fixed overlapping geometry near last secret in level 4.
• Fixed collision issue in stairs from level 11.
• Moved decoration that would get player stuck in level 11.

Controller:

• Moved Next Item to D-Pad down and fixed its flakiness.
• Added next and previous weapon controls to D-Pad right and left buttons.
• Fixed a couple settings that were not reachable.