Fixed some issues found by @Gigantoherceg, @Pietrus1745 and @olafoertelt,
Release notes v0.15.1
Features:
- staff cell will be marked if worker is not yet assigned to any building;
Changes:
- reworked main menu a bit;
Known issues:
- game stuck when pressing "Continue" button in the Main Menu after all saves were deleted;
- wrong description for "Turn on lights" contract;
- missing param in the description for "Put spacecraft into geostationary orbit" contract;
- improved base tutoril step where you turn on engines after time warp, so engines will explode less frequently;
- wrong parameter for "Leave Earth's SOI" contract.