Balance Update

[h3]New features:[/h3]

• [p]On squad wipeout, nearby enemies are damaged and knocked back[/p]

[h3][/h3][h3]Balancing:[/h3]

• [p]Third tier recruitment rank upgrade is now 25 ducats (instead of 100)[/p]
• [p]Horde units (Carver, Hurler, Petard) now require 3 units to tier up again (instead of 5)[/p]
• [p]Tweaked down threat enemy stat increases[/p]
• [p]Tweaked down enemy spawn rate escalation on boss floor[/p]

[h3][/h3][h3]Fixes:[/h3]

• [p]Mortar projectile indicator is now rendered above units[/p]