Update: added note about recent Kdenlive issue with ShuttlePro.
Update: added note about ShuttlePro not working with certain Kdenlive 15.04.x and 15.08.x versions.
Update: added note about fixing Kdenlive/Qt crashes when using the ShuttlePro.
Luckily, the old method of adding udev rules specifically for the ShuttlePRO v2 isn't required anymore. More so, as I then set the access rights to world readable&writable ... yes, that's bad. Albeit not so much for a jog dial, so the NSA can snoop how much I like to shuttle around my raw video footage. Whatever. In addition, there's no need anymore for creating a symbolic link.
(Re)Gaining Access to the ShuttlePro v2
The only thing to do on a (freshly installed) (K)Ubuntu is to add your user account to the input group. This is quickly done in a terminal; don't forget to replace user with your user name:
$ sudo usermod -a -G input userYou'll need to log out and in again in order to make the group change become effective. Afterwards, Kdenlive should automatically find your ShuttlePro v2 when you enter Kdenlive's settings and enable jog/shuttle devices.
The above terminal command just adds you to the group input so you get access to input devices, such as the ShuttlePRO v2.
Update: Qt 5.4 (and probably later versions) cause Kdenlive to crash when using the ShuttlePro. Please see Shuttle Crash for an easy fix.
Update: Since Kdenlive 15.08.2 this bug has been fixed, so that buttons and jog/dial are working again.