tutorial_pak64-v1.6.10

Some of the changes are:

• The version and pakset name check is implemented.
• Many improvements in translations and text files.
• Tunnel issues fixed.
• Some numerical values are changed to variables in the texts.
• Many fixes and improvements.
• Some code cleaning.
• A bug when routing ships when getting the tile list.
• The logic that decided if a station existed or not in the list is fixed.
• Another bug showing incorrect name of a missing station.
• Useless code related to lines and schedule is eliminated.