support tlsv1.0 tlsv1.1 tlsv1.2

Just release v2.0.0 stable enough after #15

Merge pull request #14 from Echosong/master

cli

exclude testing and other files when archive

Support SASL AUTH OAUTHBEARER Mechanism.

for non-ascii reply-to

Merge pull request #10 from daemionfox/master

Added reply-to header to Message

add cc,bcc

base64 encode utf-8 subject

utf-8 base64 encode name