Cosmetic changes
snprintf():  If size is zero, then snprintf() should return the size of the required buffer without writing anyting.  From Sami Pelkonen
snprintf():  If size is zero, then snprintf() should return the size of the required buffer without writing anyting.  From Sami Pelkonen
include/time.h: CLOCK_MONOTONIC should depend on CONFIG_CLOCK_MONOTONIC
lib_daysbeforemonth.c: use static/const allocation whenever possible
stm32_i2c: static/const allocation whenever possible
stm32_i2c_alt: static/const allocation whenever possible
stdint.h: fix INT_LEASTxx_MIN/MAX definitions
mtd_config: use same bit field sizes as mtd_geometry_s
analog/adc: remove ADC write op