Merge pull request #39 from dbrock/master

Use set_reuse_addr in http_server
Wrap a few boost asio exceptions in fc exceptions
Fix bug in json pretty printer which broke formatting and possibly
corrupted json
Compare HTTP headers case-insensitively

See <https://groups.google.com/d/msg/nodejs/XIU55IYtfJo/feUp9Fz7p14J>