Update to spell casting

Due to feedback from the community we have made a series of minor improvements. We are working on completely revamping the spell casting system to make it much easier to use, in the mean time we have made the following improvements while the new casting system is developed. * Multiple minor tweaks to spell casting to make it more sensitive to user input and potentially easier to use. * Added in a guide for casting based on active spell displayed on left hand. *Graphical and performance improvements to try and maintain higher overall frame rates.