to accept CPU, NVIDIA and ATI jobs.
These prefs are shown only where relevant:
e.g., only for processor types for which the project has app versions,
and if it has versions for only one type, no pref is shown.
These prefs affect both client and scheduler.
The client won't ask for work for a device blocked by prefs,
and the scheduler won't send it.
This replaces earlier optional project-specific prefs for
"no CPU jobs" and "no GPU jobs".
(However, these prefs continue to be honored on the server side).
- client: if NVIDIA driver is unknown, say that rather than 0
svn path=/trunk/boinc/; revision=19194