Remove an unreachable return statement.
traits defauts are strings not object

fix #4299
Merge pull request #4297 from abhinav-upadhyay/unreachable-code

Remove an unreachable return statement.
Merge pull request #4300 from Carreau/fix-4299

Traits defauts should be strings not object
Add -r option to %load. Applying a new patch ignoring whitespace changes
removing incorrect comments
better docstring for the -r option
Merge pull request #4295 from mgaitan/1093_boundary_load_magic

Implement boundary option for load magic

`%load -r 1-10` now does what one should expect.

closes #1093
underscore missing on notebook_p4

Related with issue https://github.com/ipython/ipython/issues/4312
Merge pull request #4316 from pvilas/master

underscore missing on notebook_p4