Peltasta Tier 1

[Terotrous]

Adds the Tier 1 skills for Peltasta. There's a fair bit of complexity here as Peltasta's skills have a number of interactions with each other. For example, enemies that are swashbuckled take 10% more damage from Peltasta skills.

As such, I've introduced the concept of skill modifiers, which is a class that you can create in your skill handler to assign some properties that influence damage calculation. A fair number of other skills are currently calculating damage somewhat incorrectly and should eventually be adapted to use this system once it is implemented (one example would be Smite, which multiplies the final damage by 1.5 if the target has a certain race, this calculation should be occurring before defense calculation, as this effectively multiplies the effect of enemy defense by 1.5). Later skills will probably need more properties than this, but they can easily be added to the class without influencing existing skills.