[io] IOStream: printf now supports basic %m.nf float formatting.
[io] IOStream: printf now supports basic %m.nf float formatting.

Code size for and STM32F407 example increased by 416 bytes.

Program:    9376 bytes (0.9% Full)
Program:    9792 bytes (0.9% Full)

dergraaf/xpcc,dergraaf/xpcc,dergraaf/xpcc,dergraaf/xpcc