Fixes #182 -- update documentation to point out difference for HTTP server response
Fixes #264

Address compiler warning in is_udp.hpp, make sure -Wall is added to all targets when being built.
Fixes #233 -- update default tag as defined in the header.
Fixes #194 -- show example of proper client usage and error handling.
Fixes #172 -- do not stop accepting connections for whatever reason.
Allow overriding defaulted headers.

This change fixes the linearization of HTTP requests so that two things
happen:

- empty headers are ignored
- explicitly defining the defaulted headers will suppress defaults

Fixes #263