Minor code cleanups

[billdenney]

This is intended as a "Thank you for making the package!" Hopefully it is helpful.

When looking at the bottom of entrez_search.r, I noticed a bit of what appeared to be leftover code. So, I did a quick pass through to see if I could help with some other minor code cleanups. I found a few other typos, so I fixed those.

[dwinter]

Hi Bill,

Many thanks, I produce typos at a truly alarming rate, so any counter-pressure to cut them out is greatly appreciated!

(apologies for not yet commenting on your other issues, I probably won't have the space to check them out until early next week. I'll merge this in then too)