Fixed two long-standing bugs in character insertion.

One originating from MySQL and the other from the WoW API.

MySQL: accents are ignored in the default utf8 collation. Causes primary key conflicts when two characters with the same base letters but with accents (eg Panacea, Panaceá) are inserted. Changed to utf8_bin.

WoW API: It turns out that sometimes there are auctions attributed to ???-???, who does not exist (of course). I think these are deleted characters. Regardless, these auctions are filtered now. In the future we may have a better way to deal (eg OrphanedListings table?)
Merge branch 'master' of github.com:emallson/databases-project