ENH: Data formatting with unicode length
Closes #2612. Added `display.unicode.east_asian_width` options, which calculate text width considering East Asian Width. Enabling this option affects to a performance as width must be calculated per characters.
#### Current results (captured)

![2015-09-15 20 57 27](https://cloud.githubusercontent.com/assets/1696302/9875847/7928d98c-5bec-11e5-98d9-a218c3a6b425.png)
- [x] Basic impl and test
- [x] Series / DataFrame truncation
- [x] Perf test
- [x] Doc / Release note
