Resolve issues found by static analysis (PVS)

[demoth]

Hi Guys

I have run static analysis tool over the code of dhewm3 and found some suspicious places.
I hope this could help to find the real bugs. The list is not short and probably should be addressed in batches.

Attaching the report.
https://docs.google.com/spreadsheets/d/1cTJH3DNwhfsetZt-pTLb7nDr1SbHEcY8X377En9xBpc/edit#gid=170025750

[DanielGibson]

Thanks a lot!

BTW, can you also run it on the Dentonmod branch of dhewm3-sdk? https://github.com/dhewm/dhewm3-sdk/tree/dentonmod
It seems to have some crashes that don't happen with the vanilla game (and are not always easy to reproduce), so maybe we're lucky and PVS finds the issues ;)

[demoth]

@DanielGibson done!
dhewm/dhewm3-sdk#11

[DanielGibson]

Awesome, thanks!