[Coco] CMOC 0.1.86 is out: Support for floats via MC6839 ROM

[Sean Conner]

It was thus said that the Great Pierre Sarrazin via Coco once stated:
> - Adds experimental command-line option --mc6839, which allows
>   single-precision floating point operations, by adding the 8k
>   image of Motorola's MC6839 ROM. Those operations are then
>   independent of Color Basic's floating point routines, and
>   Basic does not have to be present. When using this option,
>   the use of the %f placeholder in a printf() statement requires
>   calling enable_printf_float() at the beginning of main().

  I've been playing around with floating point on the 6809, using both the
MC6839 and Color BASIC rom routines, and I found the Color BASIC ROM
routines to be twice as fast than the MC6839:

	https://boston.conman.org/2024/03/01.1

I'm not sure why that would be the case (and double precision math is twice
as slow as the single precision math on the MC6839).  

  -spc