Better minimap buttons

By SomeTroglodyte:
- Draw borders under pixel units
- Fix rare NextTurnButton crash

Improve unconstructable improvement suggestions - By doublep

By alexban011:
- Disable state-changing buttons for puppet cities
- Add optional on-screen buttons to zoom in and out

Corrected some broken policy uniques - By OptimizedForDensity

Dynamically adjust StatsTable height - By itanasi

Fix multiplayer turn checker writing to wrong locations - By Azzurite