New Feature: HealthCheck.java

 Usage:
    player.health: ">50 <100"
    victim.health: ">50 <100"

 Accepts: =. <, <=, >, >=, %

Example:
    ANY_BLOCK:
            - tool: wool@red
              trig: left_click
              player.health: "=100%"
              message: "%p is at full hitpoints"

            - tool: wool@red
              trig: left_click
              player.health: <50% >0.5
              message: "%p has less then half hitpoints"

            - tool: wool@red
              trig: left_click
              player.health: =0.5
              message: "%p has half a heart left!"