CGE2: Fix possible null pointer dereference.
CGE2: Remove more checks on the return value of new
CGE2: Rename classes representing quit menu choices.
CGE2: Fix memory leak concerning the quit menu.
CGE2: Silence GCC warning concerning destructors of Choice's children.
CGE2: Fix mismatched new/delete pair in Sprite::ghost() and snGhost().
CGE2: Add RTL support.
CGE2: Add autosave functionality.
CGE2: Misc cleanup
CGE2: Rearrange content of saveload.cpp and cge2.h a bit.
CGE2: Remove #if 0-s.