Added functions to allow user to blacklist, and unblacklist hosts by hostname.
Changed comparator and make hostname const
Modified blacklist to hash_table for constant time lookup.
Error in which host was blacklisted if not in table. Fixed
Changed function names for consistency.
Returning if blacklisted to prevent further worker changes
Foreman may not be blacklisted.
Merge pull request #467 from nhazekam/blacklist

Added functions to allow user to blacklist, and unblacklist hostnames