[SP/JK2] Removed assertion failure caused by skipping cinematic on artus_mine too quickly
[SP] Fixed crashing on Com_Error

Conflicts:
	code/rd-vanilla/tr_init.cpp
[SP] JK2: Fixed savegames (again..)

Conflicts:
	codeJK2/game/G_Timer.cpp
[SP] Fixed compilation issues caused by merging from JK2:HD
[MP] Fix crashing when mixing C/C++ runtimes

This commit fixes crashing when mixing C/C++ runtimes between the engine
binary, and renderer library. This was due to sharing C++ objects between
the two which is generally bad, unless said object is pure virtual.