Merge branch 'plugins' into dev

rel/files/plugins.config

@@ -1,16 +1,16 @@
 [
-% {emysql, [
-%    {pool_size, 4},
-%    {host, "localhost"},
-%    {port, 3306},
-%    {username, "root"}, 
-%    {password, "public"},
-%    {database, "mqtt"},
-%    {encoding, utf8}
-% ]},
-% {emqttd_auth_mysql, [
-%    {user_table, mqtt_users}
-% ]}
+ {emysql, [
+    {pool_size, 4},
+    {host, "localhost"},
+    {port, 3306},
+    {username, "root"}, 
+    {password, "public"},
+    {database, "mqtt"},
+    {encoding, utf8}
+ ]},
+ {emqttd_auth_mysql, [
+    {user_table, mqtt_users}
+ ]}
 %
 % {emqttd_dashboard, [
 %    {listener,