Write headers directly to client connection.
Use loops to write headers to client.
use range instead of for loop
no need to allocate slice of byte slices
check for errors on each conn.Write
Add Retry as method instead of header
retry message retry field has type time.Duration
Merge pull request #10 from stuartnelson3/master

BREAKING CHANGE: Rename SendMessage method to SendEventMessage.
Add SendRetryMessage method to control client reconnecting delay.
Write headers directly to client connection.