Header-only library for conversion to/from half-precision floating point
formats.

Features:
* Supports IEEE and ARM alternative half-precision floating-point format
  o Property converts infinities and NaNs
  o Properly converts denormal numbers, even on systems without denormal support
* Header-only library, no installation or build required
* Compatible with C99 and C++11
* Fully covered with unit tests and microbenchmarks