change 2d plotting to use svg=True by default... once upstream bugs are fixed

[williamstein]

2d plotting uses svg=False by default because of a bug in Chrome which is hit by the matplotlib renderer. The following svg=True draws nothing, but with svg=False, draw a single vertical line:

 show(line([(10,0), (10,10)],axes=False), svg=True)

Links:

• The matplotlib issue about this
• The open Chromium issue about this

Ideas to fix this: somehow hack matplotlib to get around this, change our renderer (e.g., write a whole new renderer using something like maybe <svgjs.com> that completely avoids using matpltolib, for enhanced interactivity), or fix the bug in chrome.

I don't like using png's that much, since they look crappy on my HiDPI display...

[mdboom]

Chrome 33 no longer seems to have this bug.

Safari 7 does.

[williamstein]

Yeah Chrome!! Finally.

Safari... is like Chrome-- these days.