Combo skill updates
- Cleaned up skill_combo so it's easier to understand and update
- Monk updates (bugreport:9364, bugreport:4534)
  * Default combo delay is now (1000 - 4*AGI - 2*DEX) milliseconds, it will be used when none is specified in the skill_cast_db.txt
  * Fixed DEX increasing combo delay rather than decreasing it
  * Fixed "Triple Attack" not giving any "can act" delay so you were able to use a skill right when it triggered
  * Fixed combo delays of all combo skills (turns out they all use the default in both pre-re and re!)
  * Fixed "Palm Strike" in renewal having cast time rather than cast delay
  * Monk Spirit now reduces the SP cost of all Monk/Champion combo skills to 2 SP
- Taekwon updates (bugreport:9364)
  * Stances will no longer give you walk delay when they trigger
  * You can still use the Kick after moving as long as it's still within the combo delay
- Hunter updates (bugreport:9082)
  * Beast Strafing is now a target skill, you can target any brute or insect monster with it regardless of your previous target
  * You no longer need to target a brute or insect monster with Double Strafe for the combo to trigger
  * If the combo triggers you no longer get walk and attack delay (that means you can still use DS continuously)
  * You can still use Beast Strafe after moving as long as it's still within the combo delay