Detect and send locale to Presto

[markisaa]

We currently do not use the HTTP header that Presto wants for locale information. We should investigate the proper format to send and do so.

See the Presto Client for more details. There should be a comment already in the source with a link to the method the Java client uses to determine this information.

[markisaa]

I was given these links as references for this task:

http://tools.ietf.org/html/bcp47
prestodb/presto@ac24dfd