Added support for UPD/TCP communication to graphite

Graphite communication is now configurable to be either tcp or udp.
An attribute is added to the <graphite /> configuration tag that decides whether to use UDP og TCP when sending data to graphite.

Also includes a bug fix which adds a "\r\n" after each line sent to graphite in both UDP and TCP. The UDP part is untested though.
extra bonus points for adding two consts for holding the values "UDP" and "TCP" :)