allow chains and residues to be passed to viewer.fitTo
allow chains and residues to be passed to viewer.fitTo

Per suggestion by @Traksewt.

biasmv/pv,biasmv/pv,yuhangwang/pv,CyrusBiotechnology/pv,Traksewt/pv,CyrusBiotechnology/pv,yuhangwang/pv,biasmv/pv,Traksewt/pv,CyrusBiotechnology/pv,biasmv/pv,CyrusBiotechnology/pv,Traksewt/pv,yuhangwang/pv,yuhangwang/pv,Traksewt/pv