v1.3 - fix for new MT version

Changes to the mod itself

• Fixes error on new MT version which uses minetest.register_on_mods_loaded instead of minetest.register_on_connect
• Added error message if server restricted CSM from sending chat message

Changes to documentation

• Updated all instances of my old name
• Added v1.3 release note
• Added new section "It does not work!"