Weaker Cities for Vox Populi 1

- Buildings provide ~25% less Defense and ~50% less HP to Cities.
- Palace bonus lowered to 200 (default 300)
- Land units blockade adjacent undefended tiles.

The following are included in the sql but disabled (commented out), you can enable them by removing the dashes before UPDATE .
- Default city strength lowered to 400 (default 500)
- Hill bonus for cities lowered to 100 (default 200)