[SP] Fix invalid "dll" being loaded on non windows systems with regards to jk2 vs ja.

Still had leftover com_jk2 check instead of preprocessor define.
[SP] Install the JO renderer on OSX with JO not with JA.
Merge branch 'master' into rend2
[MP] Rend2: Update to ioquake/ioq3@375f6247d4faf4a2a4d14885213d1cf7516b453d , ioquake/ioq3@b099255748edaec547242e7f165c4016a8bad69b

Also fixes bug where leftover `len` variable was being set still for no reason in R_LoadVisibility.
[MP] Rend2: Make sure to use ri-> here instead of ri.  Oops.
[MP] Rend2: Accidental merge of backEnd.viewParms.or should be backEnd.viewParms.ori.
[MP] Rend2: Always clamp check ambientlight even when hdr is on.
[SP] Disable some JA hardcoded real cvars in UI if running JK2 mode.
[MP] Fixed an issue introduced during server side demo addition which introduced player colors and extended ascii being stripped from names.

This didn't show up in-game but it would have showed up in external tools receiving the player list /serverstatus, ingame browser player list, or rcon status etc.
Merge branch 'master' into rend2
[MP] Rend2: Fix more build warnings under OSX.
[MP] Fix negative index offset on x64 systems
[SP] Fix negative index offset in x64 systems
[MP] Rend2: Fix anisotropic texture filtering.