PLEASE UPDATE YOUR CONFIG.YML AND LANGUAGE FILES BEFORE UPDATING. Check the main page.
I call this a 1.5.0 and not 1.4.9 because the plugin will work almost exactly like before for default users.
CHANGES:
Drastically improved almost everything in the code, from readability to performances :
Players datas are now saved on period (every 5 mins by default, can be changed in config.yml) instead of on every events. This was the most important issue with my unknowledge of java ^^
Displaying the previous tier or/and karma will not make a request in files/database.