DOC: Another semicolon fix v0.15
Sorry for basically duplicate pr, noticed this one after.

np. ok, why don't I leave open if you have any more changes. pls ping when ready.
 @jreback I went in and added ticks to a lot of identifiers. I tried to follow the convention of the rest of the changelog. Let me know if there are any major mistakes.

Also, do I need to squash these 2 commits? I got my commits down to 1 commit, but am unsure if I need to do anything else in git.
 merged via https://github.com/pydata/pandas/commit/685eb0d73863562d56b1bf119a18709615e2739f

thanks!
