Merge pull request
#4230 from fperez/mpl-backends...
Merge pull request
#4230 from fperez/mpl-backends
Switch correctly to the user's default matplotlib backend after inline.
If '%matplotlib inline' was called first, we'd incorrectly revert to
inline when plain '%matplotlib' was called, instead of loading the
user's default GUI. If the user called '%matplotlib' first (without
'inline') it worked correctly, but not in the other order.
The fix is to read the backend from the original defaults, not from
the runtime data structure.
Requires matplotlib 1.1
