map_aes: Loop through a list of grouped variables and assign class "uneval" to each
element in the group.
Description
This is essentially aes() from ggplot2 placed inside of an
lapply() loop. The function name is passed in an mapply() loop
inside of aes_loop() and aes_loop2().
Usage
map_aes(lst)
Arguments
lst
A list of grouped variables to be assigned class uneval