Update v1.2.2: improvements and bug fixes

Release notes (v1.2.2):

• Fixed a bug where the merger block wouldn't output a laser when one input laser had been indirectly disabled by a pusher block
• Platforms 34: A new achievement has been added to the sliding puzzle (thanks to Xebulin)
• Platforms 34: Fixed the achievement "All solutions (2)", which was possible to achieve with the same solution