clang-format: increase indentation to four spaces
clang-format: increase indentation to four spaces

Also disallow short, single-line functions.

Based on feedback in the mailing list: https://groups.google.com/forum/#!topic/projectchrono-developers/gc29fJGwlUw
rserban/chrono,tjolsen/chrono,projectchrono/chrono,tjolsen/chrono,armanpazouki/chrono,armanpazouki/chrono,PedroTrujilloV/chrono,andrewseidl/chrono,PedroTrujilloV/chrono,tjolsen/chrono,projectchrono/chrono,jcmadsen/chrono,jcmadsen/chrono,rserban/chrono,jcmadsen/chrono,jcmadsen/chrono,armanpazouki/chrono,tjolsen/chrono,hsu/chrono,dariomangoni/chrono,andrewseidl/chrono,armanpazouki/chrono,amelmquist/chrono,jcmadsen/chrono,Milad-Rakhsha/chrono,rserban/chrono,Bryan-Peterson/chrono,projectchrono/chrono,dariomangoni/chrono,projectchrono/chrono,hsu/chrono,rserban/chrono,hsu/chrono,dariomangoni/chrono,andrewseidl/chrono,amelmquist/chrono,rserban/chrono,hsu/chrono,Bryan-Peterson/chrono,projectchrono/chrono,projectchrono/chrono,Milad-Rakhsha/chrono,Milad-Rakhsha/chrono,PedroTrujilloV/chrono,armanpazouki/chrono,PedroTrujilloV/chrono,dariomangoni/chrono,PedroTrujilloV/chrono,jcmadsen/chrono,Bryan-Peterson/chrono,armanpazouki/chrono,Bryan-Peterson/chrono,jcmadsen/chrono,Milad-Rakhsha/chrono,dariomangoni/chrono,amelmquist/chrono,amelmquist/chrono,tjolsen/chrono,amelmquist/chrono,rserban/chrono,hsu/chrono,andrewseidl/chrono,dariomangoni/chrono,andrewseidl/chrono,Milad-Rakhsha/chrono,Milad-Rakhsha/chrono,amelmquist/chrono,Bryan-Peterson/chrono,rserban/chrono