Author: Huong Nguyen
MDL-80380 admin: Support Microsoft XOAUTH2 for outgoing email
http://git.moodle.org/gw?p=moodle.git;a=commit;h=6abea88dac762baf1d11bdd536fd3b09a9d0c93e
http://github.com/moodle/moodle/commit/6abea88dac762baf1d11bdd536fd3b09a9d0c93e
+ 4.5 en [issuersmtpsystememail,tool_oauth2]
+ 4.5 en [issuersmtpsystememail_help,tool_oauth2]
+ 4.5 en [issuerusein_help,tool_oauth2]
+ 4.5 en [issueruseinsmtpwithoauth,tool_oauth2]