BM62 isProgramMode should return true or false

[vulcu]

System shutdown and sleep should be handled by the calling function and not the BM62 driver method. This method should return true or false when called, calling low-level commands like cli(); introduces a platform dependency (in this case, Atmel ATmega) to the driver code.

opossum/opossum/BM62.cpp

Line 231 in 2c2d131

void BM62::isProgramMode(void) {