Fix MSVS 2005 and 2008 missing size_t typdef.

Replace manual size_t typedef with stddef.h include

Fixes #128, #141.
Update AUTHORS
Add a simple utility to dump events as they happen
Add on_status_complete callback.

Add a "status complete" callback to support Simple-Response handling with HTTP
version <= 1.0.

Patch by Tóth Tamás, tests by Corey Richardson.
Update AUTHORS and .mailmap
Move url_parser.c to contrib/
doc: add travis build status link
Update AUTHORS and .mailmap
Bump to version 2.1
build: set SONAME in shared object file

Fixes #151.