Posted a balancing and bug-fix update!

Major changes:

• You now receive double the resources for delivering to a warehouse!
• All citizens now build a new home (making it go faster)
• Garages now cost 10 stone instead of 20

Minor changes:

• fixed two crashes (involving removing tracks and delivering to the final monument)
• Generation now makes sure there is always enough rock to finish level 4
• choo-choo sounds are now less loud
• building on depleted rock-deposits is now allowed
• made the tutorial more clear
• small bug-fixes and tweaks

Also, Tijmen got the first world-record: 1h 34m 48s! Should be beatable with this new update though