bApproximate is left over from long ago when the method to retrieve the system time might be 32-bit only or need correction. This is no longer needed, and already commented out of several sections of the sm5.1 base code. It can't be removed all at once just by deleting every instance of bApproximate, because it often refers to pointers that go elsewhere. so, this is the first part of a multi-stage removal process.
Other changes: remove samplerate() macro from RageSound, change some implicit casts to explicit.
Summary of changes
1) Fix issues in RageTimer and RageSoundPosMap
2) Calculate seconds from microseconds more accurately
3) Replace lrint(x) with static_cast<int>(x+0.5) for better performance
4) Replace C style casting with C++ style casting
5) Make important values 64-bit wide
6) Update RageUtil.cpp (timer conversion RStrings had some math which needed to be fixed after fixing RageTimer's math)
7) Ensure floating point math is done as floating point
8) Improve code commentary all around
9) Improve clarity and efficiency of RageSoundPosMap "return closest position" error logging
- Remove checking for standard functions from the build system
- Prefix all invocations with std::
- Replace suffixed functions with unprefixed versions
- Include <cmath> in all files that use it and remove the global include
e.g. floorf(x) -> std::floor(x)
