Added HTTP protocol

Added HTTP Protocol. 
Added property (MetricName) to customize the metric name.
Removed UDP connection since KairosDB does not support UDP.
Added documentation for the properties in README.md.

This change is not backward compatible for a couple of reasons:
1.  Renamed "TCP" to "TELNET" since both Telnet and HTTP are TCP protocols.
2.  Removed HostPostfix and MetricPrefix properties and added MetricName property instead.