remove extra spaces in front of function arguments

[baeolophus]

extra space between mean and (x) in several lines around summaries:

PlotInR/extended_visualization_in_ggplot2.R

Line 503 in ebe6613

fun.ymax = function (x) {mean (x) + sd(x, na.rm = TRUE)}, #na.rm = TRUE is not necessary with our dataset, but here to make it compatible if you use it on another dataset that contains NAs