This fixes two things.

First, the extension had to be reloaded to import the extension.
Fixes issue sympy#3619

Second, this has been broken since IPython moved IPython.zmq to
IPython.kernel.zmq. This fixes this. Note, there are some git
versions of IPython where this will still break, but it should work
for all stable releases and will work for the current git version.

Removes checks on whether or not one is in the qtconsole or notebook
before setting the unicode and latex once it is verified that your in
any IPython instance.

Adds tests for the loading of the printing extension for IPython. This
only tests the plain text output, this could also be used to test
whether or not latex is enabled, png's are created, etc.