v1.5.7

• File browser now accepts case-insensitive input
• File browser now accepts full file paths as input
• File browser now accepts filenames without extension as input for convenience (e.g. entering "asd" as input to select "asd.txt")
• Added ShowFileOverwriteDialog (see online documentation)
• Added CheckWriteAccessToDestinationDirectory property (see online documentation)
• UnauthorizedAccessException is omitted when browsing system-protected directories
• Some background sprites weren't fully opaque (%1 transparent), fixed
• Added SpriteAtlas asset for sprites