* Remove fix16.h/cpp and utilise library from m_fixed.h.
* Extend m_fixed.h with two inline functions for int to/from float operations.
* Replace fix16_floor operations with those from xs_Float.h
* Replace multiple Q16.16 conversions from 0 to just be 0.
* Replaced all found in-game bit-shifts and multiplications/divisions with inline functions from m_fixed.h
* Replaced many casts of FRACUNIT as double in SW's panel.cpp as it is converted to double by way of type promotion.
* Fixed missed precision fixes in SW's panel.cpp where some types weren't declared correctly.
* Replaced 100+ `Cos()/Sin() >> 16` operations for Blood with inline functions `CosScale16()/SinScale16()`.
* Player movement is close, but not exactly as it was. Requires more work if it is to be considered.
# Conflicts:
# source/exhumed/src/exhumed.cpp
# source/exhumed/src/ps_input.h
Currently the bit fields are still separate and they have to be merged, but for now the added memory does not matter.
Having this structure in the common parts will allow work on consolidating the input code, though.
- Input velocity now consistent irrespective of frame rate.
- Angle and horizon calculated at frame rate.
- Replace usage of F16() macro with fix16_from_int() in GetInterruptKeys().
Note: Known issues with look up/down keys that is to be repaired.
