scrape_cdp: Scrape ChemiDPlus
In meerapatelmd/skyscraper: Scrape Clinical Drug Data

The general scrape function is modified to scrape using the special parameters that ChemiDPlus requires to avoid errors.

scrape_cdp(
  x,
  options = c("RECOVER", "NOERROR", "NOBLANKS", "HUGE"),
  sleep_time = 3,
  verbose = TRUE
)

`x`	A string, a connection, or a raw vector. A string can be either a path, a url or literal xml. Urls will be converted into connections either using `base::url` or, if installed, `curl::curl`. Local paths ending in `.gz`, `.bz2`, `.xz`, `.zip` will be automatically uncompressed. If a connection, the complete connection is read into a raw vector before being parsed.
`options`	Set parsing options for the libxml2 parser. Zero or more of RECOVER recover on errors NOENT substitute entities DTDLOAD load the external subset DTDATTR default DTD attributes DTDVALID validate with the DTD NOERROR suppress error reports NOWARNING suppress warning reports PEDANTIC pedantic error reporting NOBLANKS remove blank nodes SAX1 use the SAX1 interface internally XINCLUDE Implement XInclude substitition NONET Forbid network access NODICT Do not reuse the context dictionary NSCLEAN remove redundant namespaces declarations NOCDATA merge CDATA as text nodes NOXINCNODE do not generate XINCLUDE START/END nodes COMPACT compact small text nodes; no modification of the tree allowed afterwards (will possibly crash if you try to modify the tree) OLD10 parse using XML-1.0 before update 5 NOBASEFIX do not fixup XINCLUDE xml:base uris HUGE relax any hardcoded limit from the parser OLDSAX parse using SAX2 interface before 2.7.0 IGNORE_ENC ignore internal document encoding hint BIG_LINES Store big lines numbers in text PSVI field
`sleep_time`	Time in seconds for the system to sleep before each scrape with `read_html`.
`verbose`	When reading from a slow connection, this prints some output on every iteration so you know its working.