Make display in the REPL

[oxinabox]

If one is using Compose in the REPL then nothing will be displayed.
Unless you have Gadfly loaded then it will display.
because Gadfly adds a display to the display stack and declares that it accepts Compose's Context objects.

It might make sense for that most of that code to be moved to Compose.jl
and Gadfly just to make a few overloads that extract the Context from a plot. for displaying

The code in Gadfly is here
https://github.com/GiovineItalia/Gadfly.jl/blob/72e4b92c6c591d3a3d58ceef1287e7514da62dd2/src/Gadfly.jl#L994-L1085

It would close this issue oxinabox/ProjectManagement.jl#18 which occurs because ProjectManagement.jl uses Compose bug not Gadfly