early DTLS handshake failures would not terminate the read
loop and cause the remaining handshake bytes to be feed to
packet reader, causing an error assertion.
Rework the main read loop to terminate it when the read
event is not longer active and stop the read event on
handshake failure.
Also, make the DTLS handshake erorr message a bit more readable
by appending the WolfSSL error message to it.
Fixes issue #8.
Rename all remaining CyaSSL API references to WolfSSL.
Newer WolfSSL have significant DTLS fixes and security
improvements. Continuing to support old CyaSSL releases
would impact the perfomance of encrypted WTP sessions.
