To uninstall unclutter just follow these instructions.
/ubuntu/vivid/universe///install/index.html hides the mouse cursor in X after a period of inactivity Ubuntu 15.04 universe/x11 8-19
sudo apt-get remove unclutter
Which will remove just the unclutter package itself.
sudo apt-get remove --auto-remove unclutter
This will remove the unclutter package and any other dependant packages which are no longer needed.
If you also want to delete your local/config files for unclutter then this will work.
sudo apt-get purge unclutter
Or similarly, like this unclutter
sudo apt-get purge --auto-remove unclutter
|Description||hides the mouse cursor in X after a period of inactivity|