created stub for NIST parser
added several required imports
new_compound_request now returns a Request with a searh URL
NIST now scrapes the symbol table for later use
search NIST exclusively for phase change data
added code to recognize various table formats
created function to start scraping the aggregate data table
added function to scrape transition tables
added function for most generic tables
added function to scrape table for Antoine equation parameters
fixed scraping of unit for two kinds of tables
removed logging of Result objects in debug messages because pointless
altered scraping of aggregate data to test for and request url to individual data points
NIST scraper now handles urls with individual data points
added uncertainty to results from scraping individual data points urls
conditions in name (split by ' at ') are now moved to condition field for individual value page and aggregate data table
added scraping for generic info except for synonyms
added ignore list
NIST now logs an error if chemical name is not found
if synonym name matched in search instead of primary name, emit primary name as synonym