just import full dplyr and ggplot2

[MarcinKosinski]

Documentation isn't cleaner and easier to read, nor NAMESPACE where you import almost every single possible function from dplyr or ggplot2
https://github.com/MI2DataLab/factorMerger/blob/master/NAMESPACE#L26-L82.

I recommend just to simply roxygenize the

#' @import dplyr
#' @import ggplot2

somewhere in the documentation.

More over I've noticed dplyr imports in many files with redundant calls.

[MarcinKosinski]

@durszlaczek