Used Gridplot to provides subplots support to mpl. Implementation 2x2-specific, we need to generalize.
Added basic functionality to deal with the grid geometry. Bonus: code templated.
Used add_plot session method instead of the old plotcontext.children.append, after land of #427 on master.
Added subplot example.
Fixed some unused imports and comments.
Fixed the example to render labels at the yaxis.
Deleted rendered examples.
Merge pull request #431 from damianavila/subplots

Subplots support in mpl