Changes:

[ +] Added @<Name> to mention in Chat + Sound + Message on Screen with on/off option via config
[ +] Added /enderchest which opens your enderchest + on/off via config
[ +] Added /workbench which opens a workbench + on/off via config
[ +] Added /fly which toggles your flight mode + on/off via config + permission
[ +] Added /gamemode <1,2,3,4> which switches between gamemodes + on/off via config + permission
[ +] Added /heal which refills your health and hunger + on/off via config + permission