Divided the mesh quality filter

The original implementation of the MeshQuality filter created one large kernel with a switch statement that jumped to the code of the metric actually desired. This is problematic for a couple of reasons. First, it takes the compiler a long time to optimize for all the inlined cases of a large kernel. Second, it creates a larger than necessary function that has to be loaded onto the GPU to execute.

The code was modified to move the switch statement outside of the GPU kernel. Instead, the routine for each metric is compiled into its own kernel. For convenience, each routine is wrapped into its own independent filter (e.g., MeshQualityArea, MeshQualityVolume). The uber MeshQuality filter still exists, and its use is still encouraged even if you only need a particular metric. However, internally the switch statement now occurs on the host to select the appropriate specific filter that loads a more targeted kernel.