Added new board: stm32f411re_nucleo

Makefile

miosix/Makefile

miosix/_doc/textdoc/Changelog.txt

miosix/_examples/sad_trombone/Makefile

...ch/common/CMSIS/Device/ST/STM32F4xx/Include/stm32f411xe.h

...arch/common/CMSIS/Device/ST/STM32F4xx/Include/stm32f4xx.h

miosix/arch/common/drivers/serial_stm32.cpp

...x/arch/cortexM4_stm32f4/common/interfaces-impl/delays.cpp

...cortexM4_stm32f4/stm32f411re_nucleo/core/stage_1_boot.cpp

.../stm32f411re_nucleo/interfaces-impl/arch_registers_impl.h

...rtexM4_stm32f4/stm32f411re_nucleo/interfaces-impl/bsp.cpp

...xM4_stm32f4/stm32f411re_nucleo/interfaces-impl/bsp_impl.h

...ortexM4_stm32f4/stm32f411re_nucleo/stm32_512k+128k_rom.ld

miosix/config/Makefile.inc

...arch/cortexM4_stm32f4/stm32f411re_nucleo/board_settings.h