This reverts commit e19196a8.

Apparently overflows less often

Actually, lets just fix FixedHypot instead.

Now FixedHypot uses the code from R_PointToDist2, and R_PointToDist2 just calls FixedHypot.

Ultimately, this branch was intended to get rid of a redundant way to retrieve distance and replace it with the one that was actually good at its job. So consolidating FixedHypot and R_PointToDist2 together is just an extension of that.

I needed to update it to make it functional with the precise timer. But I also
got sick of looking at the mess of sprintf followed by draw call.

- Added render flags (see r_defs.h)
- Implemented floor splats
- Drop shadow sprite rendering through render flags

The old name made it really easy to accidentally read
R_IsPointInSubsector as R_PointInSubsector, and anyway it
didn't even make sense...

This reverts commit cd957d84.