This fixed a bug where in some cases the parser could dereference
past the end of the caller provided buffer. The unit test is
improved to allocate memory in separate pieces for the split-buffer
matrix test, to give address-sanitizer more to work with.
A new concept Parser is introduced with routines to read from a stream
into the parser. This solves a problem with the old read interface where
messages must be default constructible and move assignable.
Parser fixes:
* Fix detect invalid reason-phrase octets
* Fix write_eof to set the 'complete' state on success
* Fix consider parse complete if eof received on empty body
WebSocket:
* Increase coverage
* Don't include the test code in coverage reports
* Add test code for missing coverage
Other:
* Improve the README.md
* Fix warning in sha1_context
* Tidy up the examples use of namespaces
* Various fixes to documentation and javadocs
The version field is moved into message_v1, all public interfaces
are reworked to identify HTTP/1 wire format operations (suffix "_v1")
versus general HTTP.
