Add a convenience typedef for ChSharedPtr<ChAsset> , similar to ChSharedBodyPtr in ChBody.h
Add a convenience typedef for ChSharedPtr<ChAsset> , similar to ChSharedBodyPtr in ChBody.h

PedroTrujilloV/chrono,dariomangoni/chrono,jcmadsen/chrono,jcmadsen/chrono,rserban/chrono,projectchrono/chrono,jcmadsen/chrono,hsu/chrono,dariomangoni/chrono,andrewseidl/chrono,PedroTrujilloV/chrono,jcmadsen/chrono,amelmquist/chrono,armanpazouki/chrono,rserban/chrono,hsu/chrono,hsu/chrono,armanpazouki/chrono,amelmquist/chrono,projectchrono/chrono,Bryan-Peterson/chrono,jcmadsen/chrono,amelmquist/chrono,amelmquist/chrono,Bryan-Peterson/chrono,Bryan-Peterson/chrono,Milad-Rakhsha/chrono,Milad-Rakhsha/chrono,dariomangoni/chrono,armanpazouki/chrono,dariomangoni/chrono,hsu/chrono,tjolsen/chrono,Milad-Rakhsha/chrono,PedroTrujilloV/chrono,projectchrono/chrono,rserban/chrono,dariomangoni/chrono,rserban/chrono,PedroTrujilloV/chrono,projectchrono/chrono,rserban/chrono,PedroTrujilloV/chrono,andrewseidl/chrono,andrewseidl/chrono,armanpazouki/chrono,projectchrono/chrono,jcmadsen/chrono,tjolsen/chrono,tjolsen/chrono,Milad-Rakhsha/chrono,tjolsen/chrono,rserban/chrono,Bryan-Peterson/chrono,jcmadsen/chrono,hsu/chrono,amelmquist/chrono,Milad-Rakhsha/chrono,armanpazouki/chrono,projectchrono/chrono,dariomangoni/chrono,armanpazouki/chrono,Bryan-Peterson/chrono,amelmquist/chrono,rserban/chrono,andrewseidl/chrono,andrewseidl/chrono,tjolsen/chrono,Milad-Rakhsha/chrono