prep.data: Prepare census data to generate plots
In carlopacioni/HexSimR: An R Package For Post HexSim Simulation Analysis

This function is used by other HexSimR's functions. It combines mean and standard deviation values in one data.table and add a column with the scenario name. It operates on one scenario at the time.

1	prep.data(i, means, sds, traits, scenarios, rm.T0)

`i`	The scenario position to extract
`means`	A list of data frames containing the mean values
`sds`	A list of data frames containing the standard deviation values
`traits`	A character vector with the name of the traits to be included
`scenarios`	A character vector with the scenarios' names
`rm.T0`	Whether to remove the first row of data. Relevant when it is Time Step '0' (default=TRUE)