Added y_rtaautorecord and functionality

This command will allow to keep recording RTA speedruns in the same way
as y_autorecord, with the difference being it creates new demos on death
or on save glitches (reloads).

This functionality will be enabled if y_rtaautorecord is set to 1. This
value will increment per new segment. When resetting, set it back to 1.
Or 0 to turn it off.