Update error()
Drop support for TextConversionServices

wedata's Text Conversion Services is dead.
http://wedata.net/databases/Text%20Conversion%20Services/items.json

FYI: http://web.archive.org/web/20130622171357/http://wedata.net/databases/Text%20Conversion%20Services/items
     http://web.archive.org/web/20120514004441/http://wedata.net/databases/Text%20Conversion%20Services/items.json
Drop support for Wedata

wedata is dead.
http://wedata.net/

By the way, wedata@GitHub is alive!
http://wedata.github.io/