#21 New STM32F4 C++ template, to generate multi-led blinky applications

[Liviu Ionescu (ilg)]

since testing QEMU required multi-led applications, the F4 C++ templates were extended to instantiate multiple instances of the BlinkLed object.

for multi-led boards, like STM32F4-Discovery, the code first blinks each individual led, then starts a binary count sequence using all leds.

the C templates were not changed.

also the templates for other families were not changed.