WIP: #630: Create tests for talkeditor.py following PR #605

Now that PR #605 has been merged, I would like to add some tests for the new functions I created. I will have a better idea of what steps this requires as I start experimenting, but I thought I should create this PR as soon as possible. Ultimately, this should close issue #630 .

Oct. 20, 2014: After some research, I have a slightly better idea of what I need to accomplish. These tasks might change as more information comes along -- I haven't even learned about QtTest yet.

Oct 29, 2014: After further thinking, it might not be worth it to focus on upgrading everything to Pytest just yet. For the time being, I mostly just want to get some tests done. So, I'm putting the Pytest goals on hiatus.

- [ ] Replace the Setup and Teardown functions with a pytest fixture (Hiatus)
- [ ] Adjust existing tests as necessary to conform with pytest style (Hiatus)
- [ ] Refactor talkeditor.py to make it easier to test. In particular, avoid using exec_() method.
- [ ] Write test for click_talk
- [ ] Write test for click_add_talk
- [ ] Write test for show_save_prompt
I think I'd like to refactor the code. A big part of my changes to the code was to add a new window warning the user of unsaved changes, and that uses the exec_() method. Dennis Ideler suggested changing it to setModal(True) and show(), but when I tried that, it turned out strange, as outlined in this comment (https://github.com/Freeseer/freeseer/pull/605#issuecomment-59469416). It might be a good idea for me to figure out exactly what went wrong.