Make sure that drawTilesFromQueue gets executed

For events other than move, the tile queue may not be populated yet when
updateTimeout is called. So instead of checking for the queue's length,
we register the timer unconditionally in these cases.
Merge pull request #977 from ahocevar/nice-queue

OL 2.13rc2 layer.setVisibility() with TileManager does not always work with GeoExt 1.x. r=@bartvde