Alpha 1.5.2

Changes

• Add tutorial popup with splash
• Add descriptions of all settings in README
• Add hint to FileSystemPopup
• Add warning if room images missing from xx-rooms folder
• Add popup minimizing

Fixes

• Fix weird world_xx.txt file crash
• Fix crashes with invalid xx-rooms folder
• Fix transparency issues
• Fix "Create Subregion" popup requirements
• Fix RotType tag

Full Changelog: v1.5.1...v1.5.2