FIX/ENH: topomap title

closes #1045.



![screenshot 2014-01-08 20 23 20](https://f.cloud.github.com/assets/1908618/1871706/b69fc816-789a-11e3-9771-58bdccaea61b.png)
![screenshot 2014-01-08 20 23 11](https://f.cloud.github.com/assets/1908618/1871707/b6a0bae6-789a-11e3-9908-5ab65d92f7ac.png)
![screenshot 2014-01-08 20 23 05](https://f.cloud.github.com/assets/1908618/1871708/b6b3875c-789a-11e3-8af0-44c797335970.png)

ping @TalLinzen @agramfort @Eric89GXL