refactor KernelValue Jacobian stuff (#3492)
Sync KernelGrad/KernelValue up to current state of Kernel, fix bug (#3492)
Const hints, auto vectorization comments and temps, whitespace consistency (#3492)
Merge pull request #3493 from dschwen/jacob_3492

refactor KernelValue Jacobian stuff
Merge commit '3a36125beed7c72f6dff6d6715b532e409aad14a'