Desert update (0.2.1)

Changes:

• The capacity of the vacuum has decreased significantly (USV: 1500 slots --> 200 slots)
• The inscription "MAX" is shown in the price text instead of in the map upgrade description

Bugfix

• Switching to a new map immediately after purchase caused a save error
• The size of the inscription indicating the amount of space used in the vacuum cleaner did not decrease when the number was too large