Update server.js

Better error handling

Fixed error message description

Log more details about error messages.

Updated .gitignore

Merge pull request #5 from Freeboard/cluster_support

Added cluster support

Only set host header if it's sent before.

Fixed an issue where the host header wasn't being set properly.

Added 127. to list of blacklisted hosts

Added support for X-forwarded-for and host blacklisting

Logging changes

Header changes

Header changes

Header changes