st/nine: Implement MSAA quality levels

st/nine: Implement MSAA quality levels

Advertise quality levels:
Each supported multisample count matches to one quality level.
The application doesn't know how much samples each quality level has.
For that reason it's not possible to set the multisample mask.

Return errors on quality level missmatch.

Fixes several old games not having multisample support until now.

Fix for issue #73.

Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Signed-off-by: Axel Davy <axel.davy@ens.fr>