Improve CdlPause command based on Mednafen's implementation (#207)

Reference :
https://github.com/libretro-mirrors/mednafen-git/blob/master/src/psx/cdc.cpp#L1969

This fixed an issue with Worms Pinball booting to the language screen.
Previously, it would sometimes boot to it but not reliably
and the screen would always not appear or be black.

Now, the emulator doesn't crash anymore and the language screen
can be seen (although it is a glitchy mess).