Basic .wav file reading and writing.
Convenience constructor for WavReader
Construct a WavReader from a filename.
After construction, the parameters are set and you can set them.
After that, you process the samples range-style.
Written May 15, 2020, but loosely based on code I wrote a
long time ago, at least August 2008 which is the oldest
file I have generated from the original code.
The old code could only write files, the reading support
was all added in 2020.