damage-estimator fixes-additions

[Kjus14]

Damage estimator fixes and additions

Added support for the following spells:

• Sacrier Bloodthirsty
• Cra powerful shooting buff
• Percent based healings (like Eniripsa regenerating word)

Fixed the following errors:

• Spells without critical bonuses doesn't work
• Spells with fixed damage instead of range gives bad readings
• Push damage sometimes returns floating point values. Now it is truncated
• Stacking buffs like Cra Punitive Arrow gives bad readings
• Sacrier punishment estimation is broken and returns 0 always