* Here's the skinny. Right now, a mana leech's potential gain is 40% of the post-resist damage. 
                     * The chance attached to the property is the chance of it going off each swing. 
                     * The new way it works is, the property goes off every time you swing. 
                     * Also, the chance has been scaled based on the speed of the weapon. 
                     * The fastest weapons should be about the same, but slower weapons will 
                     * actually show up with a higher % than previously possible.
                     *                     
                     * The flip side of that is, the % now represents the maximum amount of health/mana that 
                     * you get from the swing. The actual number is generated randomly, from 0 up to your leech %.
                     * 
                     * Here's a concrete example to clarify. 
                     * Let's say you currently have a katana with 50% mana leech. 
                     * That's an item property intensity of 25 (since % chance is 2xintensity). 
                     * Let's say you do an average of 15 points of damage. 
                     * The base mana yield is going to be 40% of that, or 6 points.
                     * 
                     * Currently, every other swing (subject to the vagaries of the random number generator) you will get 6 mana, period.
                     * 
                     * Under the new method, your % chance may change a bit. 
                     * Katana has a base swing speed of 2.5 seconds. 
                     * To get the new % chance, multiply the speed in seconds by the intensity: 25 x 2.5 = 62% (dropping fractions). 
                     * So every swing will generate 0-62% of your base mana yield (that's 6 mana, remember).