With strings, we don't need to care about passing in a length, since it internally stores it. So now, we don't even need a length parameter for these functions anymore as well.
This also kills off some sprintf_s calls.
For quite a while this has been causing integer division to generate a warning as error, blocking shader compiling. This means probably no one has even been running D3D in debug builds...
I tried disabling the warning with a #pragma, but it doesn't seem to apply when this flag is used.