UDP support 

Added the following:
1. Added UDP support
2. Added equals method for DatadogSeries
3. Removed http related arguments (apiKey, socket timeout, connection timeout) etc from DatadogReporter builder. As these are applicable only for http, and having it part of the reporter would give users the wrong impression that they may be applicable for udp too.
Lets go with exception. Given that package names have changed, this release is going to be backward incompatible. So this could be our last chance of moving transport specific settings to the corresponding transport, for example:  moving socket timeout/connection timeout/api key etc to http transport only.