The good old game table files got moved out of the DBC and into a folder simply named game tables, and it contains text files. I couldn't find any github, but pasted the xp.txt for you here: http://pastebin.com/raw/azAUHmTb
If there isn't API for this information, then sadly no. You'd have to make your own addon DB with the info you need. Usually people make tools to read the db/gt files and produce lua files for easy use in their addon.