Remove redundant code

[djmgit]

In lib/plotutil.py, the functions plot and plot_line has many elements in common. Try to merge plot_line into plot. Use a flag (or any other method) to determine whether a function is to be plotted or two lists of x and y has to be plotted and do both the stuff in the same function. In this way the repeated code can be removed.

[LoneOne123]

@djmgit i've done this, so when u merged the typo from me from rahuldcoder (cause i corrected this on my local already and don't want to steal his solution :D), then i will commit it and open a PR ;)
with flag u mean an additional argument to the plot function right?
greets

[djmgit]

@LoneOne123 yes, by flag I mean an additional argument.

[LoneOne123]

so sry have had an exam yesterday and my ssd died :(
now i have a bit time and have a look at all again and will solve this issue in the next days.

[LoneOne123]

@djmgit here we go, but it still just works with [array1][array2] and not with [array1],[array2]
if u want i can switch it, but i think we dont need the comma,
or i can try to make it work with both
greets

[djmgit]

@LoneOne123 no problem, its great that you are still continuing to work on this :)
Changes look good, send a PR.