Make Prediction lerping less pick + debug

- Lerping uses int rather than fixed/float comparisons
- Added debug information

Apparently, Lerping was acting up in compilers other than MSVC2013. As I can't test all of them, I added some debugging information in developer mode to assist in tracking down issues.
Likewise, constantly doing comparisons between floats and fixed point values seemed inaccurate. No idea if that will fix the issue, but there's no point in doing that anyway, when only whole units will be visually noticeable.