Merge remote-tracking branch 'remotes/origin/master' into 6.0

# Conflicts:
#	changelog.md

changelog.md

@@ -53,6 +53,7 @@ This is a major update that breaks backwards compatibility.
 * Throw an exception when trying to send a message with an empty body caused by an internal error.
 * Replaced all use of MD5 and SHA1 hash functions with SHA256.
 * Now checks for invalid host strings when sending via SMTP.
+* Include timestamps in HTML-format debug output
 
 ## Version 5.2.23 (March 15th 2017)
 * Improve trapping of TLS errors during connection so that they don't cause warnings, and are reported better in debug output

src/SMTP.php

@@ -231,7 +231,7 @@ class SMTP
                 break;
             case 'html':
                 //Cleans up output a bit for a better looking, HTML-safe output
-                echo htmlentities(
+                echo gmdate('Y-m-d H:i:s') . ' ' . htmlentities(
                     preg_replace('/[\r\n]+/', '', $str),
                     ENT_QUOTES,
                     'UTF-8'