DOC/BLD: Fix a bunch of doc build warnings that weren't being previously caught
@jreback wut do u think about the deprecation message here? merge-able?
 looks fine
 @cpcloud nothing to do with theis PR...but can you make some of the read_html ipython blocks actually be code blocks (so for example it doesn't do some of the ops., maybe the last 2 (lxml parsing and using fallback parsing), maybe even a couple of others....e.g. just give the commands, don't actually do them....

building io docs takes a lot longer now

alternatively, maybe there is a way to build docs while disabling network type things? (e.g when you are working on other docs...)?
 oh yeah duh sorry i had a thought to do this b/c of the ntwk issue.
 i wonder if there's a sphinx ext for this
 nope *sigh*
 @jreback what about using the data i've provided in the tests? (will still mark a bunch as code-block)
 eh nvm i 'll just give an exmaple using that..i need to write one for file readin ganyway
 for the docs maybe cache it (read from a static file)
 should i put in `doc/data`?
 not sure how to cache things in sphinx
 i could make a single network call, download it and trhen clean up... or two network calls...to show that passing a url works and then another to download...
 put in source/_static

where the png files r
 ok...do i need to pass the exact path or is there some sphinx magic there to just pas the filename alone and it will look there...?
 look in doc for HDF5
I do this to read in a legacy file
 thanks
