defensive; protect against sets being less than 1
use the more efficient conversion from FAQ 7.10
missed one edit in the factor to numeric conversion
fix compile_list after change to get_download. compile_list currently fails
no need for plyr in compile_list
more fallout from move to reshape2, but plus side removes the suppressWarnings
Merge pull request #27 from gavinsimpson/master

Fix `compile_list()` to work again after changes to `$counts` in object returned by `get_download()`