Move 1/rscale**nderivatives out of adjust_proxy_expression, remove...
Move 1/rscale**nderivatives out of adjust_proxy_expression, remove kernel_support_rscale, add use_rscale flag, simplify.
Move 1/rscale**nderivatives out of adjust_proxy_expression, remove kernel_support_rscale, add use_rscale flag, simplify.