use cmath not math.h
finish style change for phile::soundfile change major names to all lower case
fix formatting of readme to match library
rename README README.md
update README.md with examples
check if file handle is valid before returning format_data
check if file handle is valid before returning channel count and samplerate
use data() to access underlying data of containers, only contiguous containers support this and this is the format of the data we're expecting - add a comment to the iterator overloads to remind callers about this
store the result of std::distance rather than computing it twice
update README.md with a comment about what sort of data to pass to read/write