Improve fmt float-printing

- Fix errors printing very small numbers
 - Add explicit scientific output mode
 - Add rounding based on a specific precision for both decimal/exp
 modes.
 - Test and confirm exp/decimal against libc for all f32 values. Various
 changes to better match libc.
d8ba1bc120Marc Tiehuis committed on 4/23/2018, 5:22:51 AMparent8503eff
2 files changedLine totals unavailable