Allow model options to be passed via middleware at req.model.options.
Allow model options to be passed via middleware at req.model.options.

NolaMark/tilestream,frankrowe/tilestream,frankrowe/tilestream,mapbox/tilestream,zhm/tilestream,makinacorpus/tilestream,simonpoole/tilestream,staltz/tilestream,HydroLogic/tilestream,mapbox/tilestream,makinacorpus/tilestream,HydroLogic/tilestream,simonpoole/tilestream,zhm/tilestream,staltz/tilestream,markng/tilestream,NolaMark/tilestream,markng/tilestream