4.12.3

Modding:

• 'after [amount] turns' -> 'after turn number [amount]'
• 'before [amount] turns' -> 'before turn number [amount]'
• 'when number of [countable] is greater than [countable]' -> 'when number of [countable] is more than [countable]'
• Clean improvement queue from improvements no longer in ruleset
• Better unique documentation

Fix performance problem for displaying air units in cities

Fix 'edit existing trade' exploit

Fix console city add/remove building format - By SomeTroglodyte