Handle dryad URLs

[isteves]

Currently, because of the way the data URL for dryad is constructed, it doesn't work with our function. check_version ends up looking for nonsensical results because it keeps chunking the URL and eventually looking for anything that matches 1. I've changed the breaking point to nchar(pid) > 5 (instead of 0) to account for this to some extent. 4163fb99f6a04d1e9ef37b33030da1e9d1c52690

Not sure what the logic of dryad URL's is, so more investigation is needed!

download_d1_data("https://datadryad.org/bitstream/handle/10255/dryad.181477/experiement1.txt?sequence=1", ".")