Stop prediction from playing and stopping sounds

Player prediction would play *jump and stop falling sounds, creating odd
cases of sound repetition before the gametic caught up.
Merge branch 'master' of https://github.com/Edward850/zdoom
Merge branch 'master' of https://github.com/rheit/zdoom
- let 'showloadtimes' measure UDMF parsing.
- fixed: The 3D floor setup code treated alphas larger than 255 as translucent. This was causing problems with ZDCMP2 in GZDoom
Stall testing for interpolation

Uncapped framerate never triggered the stall detection code, as it never
tried to process a frame to start with.
Merge branch 'master' of https://github.com/Edward850/zdoom