Try at implementing dashed lines.

[lucasb-eyer]

Not working

I'd really like to have dashed lines (like 3. in #201) now that there's GiovineItalia/Compose.jl@a781354. This is my try at it, but I failed miserably. When reaching render(geom::LineGeometry ..., aes.dash is always nothing when I call plot(sin, 0, 10, dash=[5mm, 5mm]).

Really, this PR is just to get the ball rolling; feel free to ignore it completely and implement this feature the right way right away 😄

[lucasb-eyer]

(Not that cycle([]) doesn't work, thus multi-line rendering is still broken, but I don't have any more time today.)

[lucasb-eyer]

Gave it another try, but apparently I'm too stupid for this; it's just a feature request now.

It would also be nice to have hline and vline support a dash parameter. I failed at that too, see d549922: I keep getting problematic conversions from Array{Measure{MeasureNil,MeasureNil}, 1} (the type of [3mm, 5mm]) to Array{Measure{S,T},1} (what Vector{Measure} actually is and functions like Compose.strokedash expect.)

[lucasb-eyer]

Wait, what? I must've confused github by messing around in my fork.

My failed attempt is useless anyways, but I'd like to have an issue open for this. I fear it'll be forgotten if there's only #201.

[dcjones]

I didn't merge anything, was there a hash collision? So weird.

I opened a new issue for this at #392. I didn't mean for this to go ignored, sorry about that.