renderers: fix MDS/MDM LOD using frontend data in backend code

This issue is probably why the save/restore viewparms cgame system calls were added.
cgame: duplicate code removal
client: make cgame syscalls for save/restore viewparms do nothing

Comments say the save/restore viewparms system calls exists
"so we don't kill the LOD system". Which was fixed by my last commit.
Merge pull request #85 from zturtleman/model_lod

renderers: fix MDS/MDM LOD using frontend data in backend code