Switch to snprintf and sprintf in printf2

@raensink @karlj-spindance @tims-spindance please review.

We moved sprintf and snprintf to printf2-stdarg-float, reduced the number of calls to get to print an switched to sprintf/snprintf
where ever we could.  snprintf/sprintf introduced some type checking on uint32 that we had to work through.

We also cut a layer to stringfnv.

Tracing to the code all calls to print ( https://github.com/spindance/printf-stdarg-float/blob/master/source/printf2/printf2.c#L396 ) use either snprintf, sprintf, or stringfnv.

We save about 50 bytes per task.

Signed-off-by: Mike Stitt <mikes@spindance.com>