TFC more max HP from experience

A small little mod that reintroduces the obscure mechanic of gaining more max HP per experience level. Please take into consideration this was my first (technically second) ever mod and as such it's both really simple and probably has some minor bugs. The mod adds configurable values for both the max HP gained per xp level and the max level at which the bonuses apply. Going beyond this level will not increase max HP any further.