typos found in the ipython.ipynb

Spellchecking was done with:

Open JSON in vim and use the vim spellchecker:

:set spell
:set spelllang=en

There are quite a few false positives, but since they are highlighted, it is
easy to just skim through the file.

Thanks to Aaron Meurer for asking about how to spell-check ipython notebooks.
update {array_object}{operations}.ipynb again due to changes in scipy-lectures
update scipy-lecture-notes html