DOC/BLD: squash annoying sphinx bugs
carrying over from #3720

these sphinx bugs **WILL** be squashed!!
- [x] `lookup`
- [x] `to_csv` (there's a newline character here that's causing the issue. that i'm trying to figure out how to escape it in sphinx) duh use raw strings
- [x] `ExcelFile.parse`
- [x] `read_excel`
- [x] `docscrape.py: Unknown Section Example`
- [x] `docscrape.py: Unknown Section Optional Parameters`

moral of the story: when writing docstrings please follow the [sphinx rules](http://sphinx-doc.org/rest.html) _to a tee_!
