Changes:
- Purchasing max population cost increased to multiples of 5 million, to avoid extremely large armies.
- Income earned from Engineers increased from 10k to 16k.

Fixes:
- Clicking both mouse buttons at the same time would allow double transferring of items.
- Stockpile inventory being shown instead of the actual inventory.
- No access to inventories after a manual save has been initiated, to prevent item duplication.