Bug#781316: please build m-s-a with nvidia sensors support

[Vlad Orlov]

Source: mate-sensors-applet
Version: 1.8.0+dfsg1-1
Severity: wishlist

Since libxnvctrl0 and libxnvctrl-dev are in the main section
(rather than contrib), m-s-a can be safely built with nvidia
sensors support without the need to move it to contrib.

It will require a simple build-dep on libxnvctrl-dev and a new
mate-sensors-applet-nvidia binary package which will depend
on libxnvctrl0. No nvidia-settings (which is in contrib) required.