Supporting minor grid and minor ticks

[greimel]

Is it the case that gr() is the only backend that support minor grids at the moment? Is backends.jl the place to look? The only attributes containing *minor* are in gr(). I tried pyplot() and pgfplots() seem to ignore minorgrid = true.

If minor grids and minor ticks were to be implemented for other backends (and, possibly, in Makie.jl), I would like to be able to control major and minor ticks separately.

In #1788 I implemented two new attributes foreground_color_tick and foreground_color_minor_tick and incorporated them in the gr() backend.

plot(rand(10), rand(10), foreground_color_tick = :green, foreground_color_minortick=:red, minorgrid=true)

I propose to replace the foreground_color_axis attribute with these two attributes. (The color of the axis is determined by foreground_color_axis.

Should I extend #1788 to replace foreground_color_axis in the other backends?

[daschw]

Minor and major ticks grids where only implemented some months ago for GR and GLVisualize (they share the same code for drawing segments for axes, grids, ticks, etc.) in #1596.
So #1788 cannot really be extended for the other backends, right?

[daschw]

I'm sorry, of course foreground_color_tick can be extended to the other backends.